Solar System And Earth

"Earth's Twin" May Be in Our Solar System: Saturn's Moon, Titan --Hosts a Layered Atmosphere

2012-01-17T05:50:00.000-08:00

Saturn's moon Titan may be more similar to an Earth-like world than previously thought, possessing a layered atmosphere just like our planet. Titan has long held interest for scientists because of its promise, as the only known moon in the solar system that has a dense atmosphere, there has been hope that it might host some form of life. Information provided by three separate spacecraft missions sent to the area has created more speculation about the moon, which is roughly twice the size of our own (which, quite inexplicably, still has no name) but is nine times farther away from the sun and a freezzing -180°C.

The first mission was Voyager 1, which flew by in 1981, followed by Cassini in 2004, and the next year by the Huygens probe, which actually landed on its surface. Despite the massive amounts of data collected by all three vehicles and the dense athmosphere, scientists have still not been able to get conclusive evidence on what is going on with Titan’s atmosphere.

To clear up some of the mystery, the two researchers --Benjamin Charnay, a planetary scientist at France's National Center of Scientific Research and colleague, Sébastien Lebonnois-- put together a three dimensional computer model that incorporates information collected from all three space vehicles that includes among other things, chemical compositions, dune movement and measurements of wind and cloud formations and were able to conclude that Titan’s atmosphere very clearly has at least one boundary, which is the part of an atmosphere that is impacted by the surface (friction, heat, etc.) and vice-versa.

But they also found evidence that there appears to be a second boundary as well that is likely caused by changes in seasonal air circulation. The lowest layer is most influenced by a planet or moon's surface, and has greatest influence on the surface with clouds and winds, as well as by sculpting dunes found on Titan.

Earth's boundary layer, which is between 1,650 feet and 1.8 miles (500 meters and 3 kilometers) thick, is controlled mostly by solar heat warming the planet's surface. Since Titan is more distnat from the sun, its boundary layer might behave quite differently. Titan's atmosphere is thick and opaque, obscuring our knowledge about its lower layers. "This layer is very important for the climate and weather — we live in the terrestrial boundary layer," said Charnay.

Their simulations revealed the lower atmosphere of Titan appears separated into two layers that are both distinct from the upper atmosphere in terms of temperature. The lowermost boundary layer is shallow, only about 2,600 feet (800 meters) deep and, like Earth's, changes on a daily basis. The layer above, which is 1.2 miles (2 kilometers) deep, changes seasonally.

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Scientists find monster black holes, biggest yet

2011-12-06T01:37:00.000-08:00

CAPE CANAVERAL, Fla. (AP) — Scientists have found the biggest black holes known to exist — each one 10 billion times the size of our sun.

A team led by astronomers at the University of California, Berkeley, discovered the two gigantic black holes in clusters of elliptical galaxies more than 300 million light years away. That's relatively close on the galactic scale.

"They are monstrous," Berkeley astrophysicist Chung-Pei Ma told reporters. "We did not expect to find such massive black holes because they are more massive than indicated by their galaxy properties. They're kind of extraordinary."

The previous black hole record-holder is as large as 6 billion suns.

In research released Monday by the journal Nature, the scientists suggest these black holes may be the leftovers of quasars that crammed the early universe. They are similar in mass to young quasars, they said, and have been well hidden until now.

The scientists used ground-based telescopes as well as the Hubble Space Telescope and Texas supercomputers, observing stars near the black holes and measuring the stellar velocities to uncover these vast, invisible regions.

Black holes are objects so dense that nothing, not even light, can escape. Some are formed by the collapse of a super-size star. It's uncertain how these two newly discovered whoppers originated, said Nicholas McConnell, a Berkeley graduate student who is the study's lead author. To be so massive now means they must have grown considerably since their formation, he said.

Most if not all galaxies are believed to have black holes at their center. The bigger the galaxy, it seems, the bigger the black hole.

Quasars are some of the most energized and distant of galactic centers.

The researchers said their findings suggest differences in the way black holes grow, depending on the size of the galaxy.

Ma speculates these two black holes remained hidden for so long because they are living in quiet retirement — much quieter and more boring than their boisterous youth powering quasars billions of years ago.

"For an astronomer, finding these insatiable black holes is like finally encountering people nine feet tall whose great height had only been inferred from fossilized bones. How did they grow so large?" Ma said in a news release. "This rare find will help us understand whether these black holes had very tall parents or ate a lot of spinach."

Oxford University astrophysicist Michele Cappellari, who wrote an accompanying commentary in the journal, agreed that the two newly discovered black holes "probably represent the missing dormant relics of the giant black holes that powered the brightest quasars in the early universe."

One of the newly detected black holes weighs 9.7 billion times the mass of the sun. The second, slightly farther from Earth, is as big or even bigger.

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New Earth-like planet may have water, life

2011-11-28T04:17:00.000-08:00

Scientists claim to have discovered a potentially habitable planet which has an environment much similar to that of the Earth and may contain water and even life.

The exoplanet, called Gliese 581g, is located around 123 trillion miles away from the Earth and orbits a star at a distance that places it squarely in the habitable or the Goldilocks zone, the scientists said.

The research, published in the Astrophysical Journal, suggests that the planet could contain liquid water on its surface, meaning it tops the league of planets and moons rated as being most like Earth, they said.

Compelling case
“Our findings offer a very compelling case for a potentially habitable planet,” said lead researcher Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz.

“The fact that we were able to detect this planet so quickly and so nearby tells us that planets like this must be really common,” Prof. Vogt was quoted as saying byDaily Mail.

The new findings are based on 11 years of observations of the nearby red dwarf star Gliese 581 using the HIRES spectrometer on the Keck I Telescope by a team from UC Santa Cruz and the Carnegie Institution of Washington.

The team reported the discovery of two new planets around Gliese 581. This brings the total number of known planets around this star to six, the most yet discovered in a planetary system outside of our own.

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Europa’s “Great Lake”

2011-11-24T04:24:00.000-08:00

In a significant finding in the search for life beyond Earth, scientists from The University of Texas at Austin and elsewhere have discovered what appears to be a body of liquid water the volume of the North American Great Lakes locked inside the icy shell of Jupiter’s moon Europa.

The water could represent a potential habitat for life, and many more such lakes might exist throughout the shallow regions of Europa’s shell, lead author Britney Schmidt, a postdoctoral fellow at The University of Texas at Austin’s Institute for Geophysics, writes in the journal Nature.

Further increasing the potential for life, the newly discovered lake is covered by floating ice shelves that seem to be collapsing, providing a mechanism for transferring nutrients and energy between the surface and a vast ocean already inferred to exist below the thick ice shell.

“One opinion in the scientific community has been, ‘If the ice shell is thick, that’s bad for biology -- that it might mean the surface isn’t communicating with the underlying ocean,’” said Schmidt. “Now we see evidence that even though the ice shell is thick, it can mix vigorously. That could make Europa and its ocean more habitable.”

The scientists focused on Galileo spacecraft images of two roughly circular, bumpy features on Europa’s surface called chaos terrains. Based on similar processes seen here on Earth -- on ice shelves and under glaciers overlaying volcanoes -- the researchers developed a four-step model to explain how the features form on Europa. It resolves several conflicting observations, some of which seemed to suggest that the ice shell is thick and others that it is thin.

“I read the paper and immediately thought, yes, that’s it, that makes sense,” said Robert Pappalardo, senior research scientist at NASA’s Planetary Science Section who did not participate in the study. “It’s the only convincing model that fits the full range of observations. To me, that says yes, that’s the right answer.”

The scientists have good reason to believe their model is correct, based on observations of Europa from the Galileo spacecraft and of Earth. Still, because the inferred lakes are several kilometers below the surface, the only true confirmation of their presence would come from a future spacecraft mission designed to probe the ice shell. Such a mission was rated as the second-highest priority flagship mission by the National Research Council’s recent Planetary Science Decadal Survey and is currently being studied by NASA. On Earth, radar instruments are used to image similar features within the ice, and are among the instruments being considered for a future Europa mission.

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An uncertain future for solar system exploration

2011-11-21T03:26:00.000-08:00

In less than two weeks, an Atlas V rocket is slated to lift off from Cape Canaveral, propelling NASA’s Mars Science Laboratory (MSL) spacecraft towards the Red Planet. MSL—aka Curiosity—is one of the most ambitious, and expensive, Mars missions ever flown: a rover roughly the size of a Mini Cooper automobile and equipped with a suite of instruments to study Mars and learn about when it was warmer, wetter, and perhaps more hospitable to life. Its landing in August 2012 will be the capstone to what NASA calls the “Year of the Solar System”, a Martian-year-long period that includes milestones ranging from the arrival of MESSENGER at Mercury and Dawn at Vesta to the launches of Juno to Jupiter and GRAIL to the Moon.

While this is something of a golden age for planetary exploration, with a dozen active NASA planetary missions today, there is growing unease in the planetary science community about the future. There were concerns earlier this year with the release of the decadal survey of planetary science missions, which warned of a mismatch between the highest-priority missions—a Mars rover to collect samples for later return to Earth, and a Europa orbiter—and projected budgets ExoMars estrangement

The future of Mars exploration, beyond MSL, had been intended to be one of enhanced collaboration between NASA and ESA. The two agencies had agreed in 2009 to effectively merge NASA’s long-term Mars exploration program with ESA’s ExoMars effort. In 2016 NASA would launch a European Mars orbiter carrying some US instruments, to be followed two years later by the NASA launch of what was originally planned to be separate NASA and ESA Mars rovers, later merged into a single, jointly-developed rover that would cache samples for return to Earth on later missions. That would fulfill the mission of the Mars Astrobiology Explorer-Cacher (MAX-C) that the decadal survey identified earlier this year as the highest priority large, or flagship, planetary science mission in the next decade.
“The Europeans are as mad as hell,” said Hubbard of NASA’s decision not to launch ESA’s 2016 Mars orbiter.

There is evidence, though, that NASA may be backing out of that commitment. In September it informed ESA it would not be able to launch the 2016 European Mars orbiter as planned, forcing ESA officials to scramble to find an alternative approach, one that may have Russia become a partner by launching the orbiter on a Proton rocket. That decision reportedly came at the behest of the Office of Management and Budget (OMB), which also seeks to put the brakes on a joint 2018 mission.

“The Europeans are as mad as hell,” said Scott Hubbard, former director of NASA’s Ames Research Center, at a November 3 Capitol Hill forum on the future of planetary exploration jointly organized by The Mars Society and The Planetary Society. “When I talk to my European colleagues, they’re really, really upset. They feel like they’ve been swindled.”

That frustration comes after NASA and ESA had worked to lower the cost of the 2018 mission. Hubbard said the NASA cost of the mission has been reduced to $1.4 billion, more in line with a midrange New Frontiers mission. “It’s no longer a flagship-class mission,” he said, thanks to $1.2 billion provided by ESA for its role on the mission.

Hubbard believes that OMB may be misinterpreting the “decision rules” included in the planetary science decadal report on how to accommodate reduced budgets. Citing an email from someone who had met with OMB officials about the budget, MAX-C was deemed a “non-starter” by the office under current budgets even with its reduced cost, as it considers flagship missions the lowest priority of all classes of missions.

Hubbard noted that “programmatic balance”—a mix of small, medium-sized, and large missions—was a key aspect of the planetary decadal. That report, moreover, did not place flagship missions as the lowest priority. Instead, it recommended that if costs exceeded projected budgets, flagship missions should be descoped or delayed, followed by changes to the New Frontiers and Discovery programs for smaller missions.

That’s exactly what NASA has done, reducing the cost of MAX-C from its original estimate of $3.5 billion to the new estimate of $1.4 billion. “I would argue that NASA has been extremely responsive to the decadal survey and to budgetary pressure,” Hubbard said.

NASA has said little publicly about the future of its Mars exploration program and cooperation with ESA. At a news briefing last week about the upcoming MSL launch, Doug McCuistion, director of NASA’s Mars program, talked briefly about the issue. “The US and ESA realize we may have some budget concerns in the future, so ESA has approached Russia about potentially providing a launch vehicle and being involved,” he said. He declined to go into more detail because both the fiscal year 2012 budget has yet to be approved by Congress—although that may happen this week—while the 2013 budget proposal won’t be released until early next year. The subject may also come up at a hearing Tuesday on NASA’s planetary science plans by the House Science Committee.

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Solar System May Have Lost Fifth Giant Planet

2011-11-14T05:08:00.000-08:00

Astronomer David Nesvorny from the Southwest Research Institute in Texas believes that the solar system might have once contained a fifth gigantic planet, which was ejected deep into the galaxy in a moment of cosmic turmoil.

By looking at the population of the Kuiper belt — the icy-cold ring of asteroids beyond Neptune — and by studying the historical fingerprints left on the craters of the Moon, Nesvorny was able to piece together clues about our solar system’s adolescence.

He found that a dynamic instability, which occurred about 600 million years into the solar system’s life, greatly affected the orbit of our giant planets and scattered smaller bodies. Some moved into the Kuiper belt and others traveled inwards, marking their course as impacts on the Moon and planets.

But that scenario has a flaw. Slow changes in Jupiter’s orbit would have had a large effect on the orbits of the terrestrial planets. All hell would have broken lose, and the Earth could have collided with Mars or Venus. Something had to change.

“Colleagues suggested a clever way around this problem,” says Nesvorny in a press release. Instead of a slow movement, Jupiter’s orbit could have quickly changed, which would have altered the outer solar system but been less harmful to the inner planets.

Unfortunately, this too caused problems. Computer simulations, ran thousands of times, showed that Jupiter’s quick jump had the intended effect, but Uranus or Neptune was always knocked out of the solar system. “Something was clearly wrong,” Nesvorny explains.

So perhaps, instead, the early solar system could have had five giant planets instead of four. By plopping an additional giant planet with a mass similar to that of Uranus or Neptune the simulation worked as planned. Jupiter jumped into place, the inner planets remained unharmed and the outer planets stayed behind.

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How death gave birth to our solar system

2011-11-09T05:11:00.000-08:00

Our solar system was born thanks to the death of a nearby star in a spectacular supernova event, say researchers.

The findings are based on new computer simulations developed by Dr Matthias Gritschneder, from Beijing's Peking University, and colleagues, and published on the pre-press website ArXiv.org.

Gritschneder and colleagues found shock waves generated by a supernova could have caused the collapse of a molecular gas and dust cloud, eventually leading to the formation of the Sun and planets.

The model also explains unusual isotope readings in some of the oldest bodies of the solar system.

Stars and solar systems are created in the collapse of molecular gas and dust clouds.

Scientists say this is what happened to our solar system about 4.6 billion years ago, but until now they didn't know what triggered that collapse.

Clues have been found in the ratio of aluminium isotopes found in meteorites formed during the molecular cloud collapse.

Ancient meteorites
The isotope aluminium-26 usually has a half life of 700,000 years, eventually changing in to aluminium-24.

However the ratio of aluminium isotopes in ancient carbonaceous chondrite meteorites, called CV-chondrites, is unusually high.

CV-chondrites are thought to have formed directly out of the collapse of the molecular cloud that gave birth to our solar system.

The unusual isotope measurements suggest fresh aluminium-26 was being fed into this molecular cloud as it collapsed, either by stellar winds from a local star, or by the blast of a nearby supernova explosion, caused by the death of a star.

Gritschneder and colleagues say their model shows a supernova event 15 light years away was the most likely trigger.

"The blast's shock wave and hot gases travelled through space eventually colliding with a molecular cloud of cold gas and dust, causing it to quickly collapse, forming the Sun and solar system," says Gritschneder.

"It also provides the right ratios of aluminium isotopes to explain the levels found in CV meteorites."

"The CV-chondrites probably formed when the temperature of gas cloud dropped below about 1800°C," says Gritschneder.

"The model also shows how this would have occurred over a period of just 20,000 years, matching isotope measurements which act like time stamps marking the formation of these meteorites to within 20,000 years of each other."

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City Lights Could Reveal ET, Researchers Say

2011-11-04T00:40:00.000-07:00

If you look at the Earth from space, it's pretty clear that there's intelligent life here because you can pick out cities on the night side. Abraham Loeb, of Harvard University and Edwin Turner, from Princeton University, are saying that we might find other civilizations the same way.

The reason is that the way we usually listen for aliens -- via radio signals -- may not work that well. One issue is that contrary to popular belief, TV transmissions don't travel all that far. (It would actually be near-impossible to pick up old shows from more than a few light years away).

ANALYSIS: The Search For Extraterrestrial Polluters
Our own civilization is actually generating less residual energy as time goes on as communications move to optical fiber. Other civilizations may have done the same, so picking them up actually gets harder as their technology gets better.

The trick is to look for a certain kind of light that would be different from natural starlight. The two note the spectrum of LEDs and streetlights is different from that of the sun. An alien looking at Earth with a sufficiently sensitive telescope would notice that.

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Moon and planets offer triple treat on Friday

2011-10-29T05:13:00.000-07:00

Look toward the southwestern horizon just after sunset on Friday night and you’ll see a triple feature of Venus, Mercury, and the two-day old moon. And there's another planet treat in time for the pre-Halloween weekend, too.

You'll need a good low horizon and a clear sky to see the first three objects since they will be very low in the sky, less than 10 degrees up. Binoculars may help. For reference, a closed first held out at arm's length covers about 10 degrees of the night sky.

The accompanying sky map of the moon and planets here shows their locations on Friday evening.

The moon will be a razor-thin crescent, and the so-called "dark" side of the moon — actually its far side facing away from Earth, which is not always dark — should be well lit by sunlight reflecting off the Earth.

Venus should appear very bright, weather permitting. This may be the first glimpse you get of it this season, but it will soon be blazing bright every evening. Mercury will be directly under Venus.

All three objects will be very low because of the shallow angle the ecliptic — the path the sun takes across the sky — makes with the horizon on Friday. Notice that the sun is setting well to the south of the west point on the horizon, now that we're more than a month past the fall equinox.

The only days the sun sets due west is right on the equinoxes, which were March 20 and Sept. 23 this year.

A few minutes after sunset, turn around and look at the eastern horizon. You will see Jupiter rising there slightly north of due east, the brightest object in that part of the sky.

At 10 p.m. EDT on Friday, Jupiter will be opposition, exactly opposite the sun in the sky. On this night, Jupiter rises at sunset and sets at sunrise, so is visible all night long.

Binoculars or a small telescope can reveal Jupiter's four bright moons, allowing you to follow them as they constantly shift position, orbiting around the giant planet.

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Dwarf planet Eris surprises astronomers

2011-10-27T00:33:00.000-07:00

Eris, the dwarf planet whose 2005 discovery led to Pluto losing its status as a planet, has passed in front of a star, providing astronomers with the clearest view of it since it was identified.

It is about the same size as Pluto and is one of the brightest objects in the solar system, according to the new analysis, released Wednesday by the journal Nature.

Scientists' picture of Eris had remained fuzzy because its distance from Earth is so vast: It is about three times farther out from the sun than Pluto. Some estimates pegged Eris as about 25% larger than Pluto, but it was too far away to tell for sure.

"It's very difficult, because it's so small in the sky," said lead author Bruno Sicardy, a planetary scientist at Pierre and Marie Curie University and Observatory in Paris.

With such small, far-off objects, astronomers wait for what's known as a stellar occultation, in which the object will cross over a star, essentially casting a shadow over the Earth. The amount of starlight blocked by the object allows scientists to calculate the object's size.

Witnessing this stellar occultation last year required being in the right place at exactly the right moment during the brief time window that Eris was scheduled to block the star.

To spot the star-crossing, Sicardy's team asked telescope operators at 26 different sites around the world to make observations. Just three telescopes at two of those sites, both in Chile, managed to catch the event.

From the data, the researchers were able to calculate that the dwarf planet's diameter is about 1,445 miles — on a par with Pluto, which is somewhere between 1,429 and 1,491 miles across.

The fact that Eris is smaller than previously estimated means that the amount of light scientists had detected coming from it originated from a smaller-than-anticipated surface area — and therefore its surface is brighter than anyone had thought.

In fact, the new calculations make Eris one of the brightest objects in the solar system, even though its surface should have been darkened from bombardment by cosmic rays and micrometeorites.

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Doomsday comet makes closest approach to Earth

2011-10-17T04:30:00.000-07:00

ANTICIPATED by doomsayers as a potentially catastrophic event, Comet Elenin traversed the closest point in its trajectory around Earth (35,000km) early Sunday morning just before sunrise. But save for a few keen observers and astronomers, this went largely unnoticed.

When discovered by astronomer Leonid Elenin in December 2010, the passing of the 3-5 km wide chunk of space ice was predicted to be the astronomical event of the year, which in turn inspired an overkill of apocalyptic theories.

Amateur astronomers and conspiracy theorists put forth the idea that Comet Elenin was responsible for a variety of anomalous events seen throughout 2011; from the scattered outbursts of political uprisings to the earthquake in Japan.

Others extrapolated these prophecies to Comet Elenin representing the end of the world.
However, sometime during the middle of August, Comet Elenin began disintegrating as it crossed the solar system and traveled through the sun’s solar flares. And so at around 4 am Sunday morning, the comet passed within view of ground telescopes in an event that astronomers described as “largely uneventful.”

“I could see a hazy group of dim chunks of rock sitting in the sky, moving very slowly,” said Samir Nawar, a professor at the National Research Institute of Astronomy and Geophysics (NRIAG) in Helwan.

“But it was far less interesting than looking at the sun or the moon on any other day of the year, and a lot less noticeable,” he joked, referring to the Earth’s temperate climate and tides.
On the issue of conspiracy theories, Nawar went on to say that there is an obsession with space phenomena, which are far away and little understood; and that even if Comet Elenin had not disintegrated, the event would have still passed largely unnoticed. –AA

“People like to play on the fact that there are a lot of ‘maybes’ with these ‘unknown’ phenomena,” he continued. “But the truth is there are few maybes; there is a lot of accuracy with understanding space science, more than there is an understanding of what’s at the bottom of the oceans. If there was any issue of concern, NASA or any professional astronomer would be the first to raise the issue.”

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New Proof That Comets Watered the Earth

2011-10-13T06:20:00.000-07:00

By rights, the earth should not be the cosmic garden it is. In a solar system of planets and moons that are solid rock or mostly gas, shrouded in clouds or atmosphere-free, scorchingly hot or bitterly cold, there's only one that's dripping wet. Earthlings like to refer to our home planet as the solar system's water world, and it's a jolly good thing it's as wet as it is, because without plenty of water, life (at least as we know it) would be impossible.

All the same, it's likely our planet was once a far drier, dustier place. You need only look at two of our nearby rocky neighbors — Mercury and Venus — for a reminder of what living so close to the blast furnace of the sun can do to you. Our atmosphere helps us retain the abundant water we do have, but how did it get to us in the first place?

One popular theory has long been comets. The solar system swarms with these little rogue bodies — perhaps a trillion of them, according to astronomers' back-of-the-envelope estimates — and shortly after the sun and planets formed, they were everywhere, flying randomly and free to collide with anything in their way. Since comets are essentially dirty snowballs made of rock, gas and water ice, a few crash landings on earth could have provided all the water we needed quite nicely.

But there was a problem with that theory. All of the comets astronomers observed were indeed packed with water ice, but a lot of it was what's known as heavy water, in which the hydrogen in the H2O mix is an isotope known as deuterium, with one proton and one neutron in its nucleus. The hydrogen found in ordinary water has no neutron. Since the overwhelming share of the water in earth's oceans is made with the light hydrogen atom, astronomers calculated that comets could have accounted for only about 10% of what's there. Now, according to a new paper published in the journal Nature, it appears that those scientists may have been wrong — and the reason for their error is that they were simply looking at the wrong comets.

The paper, co-authored by researchers at the California Institute of Technology, is based on observations conducted by the Herschel Space Observatory, a spacecraft launched by the European Space Agency in 2009. Herschel looked specifically at comet Hartley 2, a small comet discovered in 1986 with an estimated diameter of .75 to .99 mi. (1.2 to 1.6 km). Analyzing the chemical composition of Hartley 2's corona — or the gassy veil surrounding the main comet body — Herschel discovered that its concentration of heavy water was only about half that of any comets observed before. While that wouldn't entirely explain earth's particular heavy- and light-water mix, it does bring the chemistry a lot more into line — and gives the cometary explanation for earthly water a big boost.

"Our results with Herschel suggest that comets could have played a major role in bringing vast amounts of water to an early earth," says physicist Dariusz Lis of Caltech, a co-author of the paper.

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2 Small Asteroids Zoom Between Earth and Moon's Orbit

2011-10-09T22:45:00.000-07:00

A small asteroid zipped by Earth well inside the orbit of the moon today (Sept. 30), the second space rock encounter for our planet this week. Both asteroids posed no threat to Earth, scientists say.

"Small asteroid 2011 SM173 just passed Earth at a safe distance of 180,000 miles (290,000 km or .8 lunar distance)," scientists with NASA's Asteroid Watch program announced in a Twitter post today.

Asteroid 2011 SM173 was discovered yesterday by astronomers and is about 56 feet (17 meters) wide, making it about the size of a house. Its flyby came just four days after the pass of another space rock — the asteroid 2011 SE58 —which actually came even closer to Earth.

The 33-foot (10-m) wide asteroid 2011 SE58 slipped within 147,000 miles (236,573 km) of Earth during an evening flyby on Monday (Sept. 26), according to Asteroid Watch scientists.

The average distance between Earth and the moon is about 238,900 miles (384,402 km).

No threat to Earth
Both asteroids were too small to threaten Earth with a serious impact. If they had barreled into Earth, they likely would have burned up completely in Earth's atmosphere, the researchers said.

"Rocky asteroids the size of 2011 SE58 are not considered hazardous as they break up in the atmosphere & cause no ground damage," Asteroid Watch scientists wrote.

Asteroid 2011 SE58 was discovered by skywatchers on Sept. 21, according to database maintained by NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif.

By coincidence, the asteroid flybys this week occurred just as NASA announced the latest results from its efforts to find the largest near-Earth asteroids, objects that could potentially endanger Earth.

NASA's asteroid census has discovered about 90 percent of the largest near-Earth asteroids and revealed that the population of mid-size space rocks (asteroids about 3,300 feet, or 1,006 m, wide) is far lower than previously thought.

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NASA Space Telescope Finds Fewer Asteroids Near Earth

2011-10-05T23:04:00.000-07:00

PASADENA, Calif. -- New observations by NASA's Wide-field Infrared Survey Explorer, or WISE, show there are significantly fewer near-Earth asteroids in the mid-size range than previously thought. The findings also indicate NASA has found more than 90 percent of the largest near-Earth asteroids, meeting a goal agreed to with Congress in 1998.

Astronomers now estimate there are roughly 19,500 -- not 35,000 -- mid-size near-Earth asteroids. Scientists say this improved understanding of the population may indicate the hazard to Earth could be somewhat less than previously thought. However, the majority of these mid-size asteroids remain to be discovered. More research also is needed to determine if fewer mid-size objects (between 330 and 3,300-feet wide) also mean fewer potentially hazardous asteroids, those that come closest to Earth.

The results come from the most accurate census to date of near-Earth asteroids, the space rocks that orbit within 120 million miles (195 million kilometers) of the sun into Earth's orbital vicinity. WISE observed infrared light from those in the middle to large-size category. The survey project, called NEOWISE, is the asteroid-hunting portion of the WISE mission. Study results appear in the Astrophysical Journal.

"NEOWISE allowed us to take a look at a more representative slice of the near-Earth asteroid numbers and make better estimates about the whole population," said Amy Mainzer, lead author of the new study and principal investigator for the NEOWISE project at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It's like a population census, where you poll a small group of people to draw conclusions about the entire country."

WISE scanned the entire celestial sky twice in infrared light between January 2010 and February 2011, continuously snapping pictures of everything from distant galaxies to near-Earth asteroids and comets. NEOWISE observed more than 100 thousand asteroids in the main belt between Mars and Jupiter, in addition to at least 585 near Earth.

WISE captured a more accurate sample of the asteroid population than previous visible-light surveys because its infrared detectors could see both dark and light objects. It is difficult for visible-light telescopes to see the dim amounts of visible-light reflected by dark asteroids. Infrared-sensing telescopes detect an object's heat, which is dependent on size and not reflective properties.

Though the WISE data reveal only a small decline in the estimated numbers for the largest near-Earth asteroids, which are 3,300 feet (1 kilometer) and larger, they show 93 percent of the estimated population have been found. This fulfills the initial "Spaceguard" goal agreed to with Congress. These large asteroids are about the size of a small mountain and would have global consequences if they were to strike Earth. The new data revise their total numbers from about 1,000 down to 981, of which 911 already have been found. None of them represents a threat to Earth in the next few centuries. It is believed that all near-Earth asteroids approximately 6 miles (10 kilometers) across, as big as the one thought to have wiped out the dinosaurs, have been found.

"The risk of a really large asteroid impacting the Earth before we could find and warn of it has been substantially reduced," said Tim Spahr, the director of the Minor Planet Center at the Harvard Smithsonian Center for Astrophysics in Cambridge, Mass.

The situation is different for the mid-size asteroids, which could destroy a metropolitan area if they were to impact in the wrong place. The NEOWISE results find a larger decline in the estimated population for these bodies than what was observed for the largest asteroids. So far, the Spaceguard effort has found and is tracking more than 5,200 near-Earth asteroids 330 feet or larger, leaving more than an estimated 15,000 still to discover. In addition, scientists estimate there are more than a million unknown smaller near-Earth asteroids that could cause damage if they were to impact Earth.

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Obscure Full Moon Names of 2011

2011-10-03T01:04:00.000-07:00

Jan. 19, 4:21 p.m. EST – Full Wolf Moon: Amid the zero cold and deep snows of midwinter, the wolf packs howled hungrily outside Indian villages. The Full Wolf Moon was also known as the Old Moon or the Moon After Yule. In some tribes, this was also known as the Full Snow Moon; most applied that name to the next moon.

Feb. 18, 3:36 a.m. EST – Full Snow Moon: Usually the heaviest snows fall in this month. Hunting becomes very difficult, and hence to some tribes this was known as the Full Hunger Moon.

Mar. 19, 2:10 p.m. EDT – Full Worm Moon: In this month, the ground softens and the earthworm casts reappear, inviting the return of the robins.

The more northern tribes knew this as the Full Crow Moon, when the cawing of crows signals the end of winter, or the Full Crust Moon because the snow cover becomes crusted from thawing by day and freezing at night. TheFull Sap Moon, marking the time of tapping maple trees, is another variation.

The moon will also arrive at perigee only 50 minutes later at 3:00 p.m. EDT at a distance of 221,565 miles (356,575 kilometers) from Earth. So this is the biggest full moon of 2011. Very high ocean tides can be expected during the next two or three days, thanks to the coincidence of perigee with full moon.

Apr. 17, 10:44 p.m. EDT – Full Pink Moon: The grass pink or wild ground phlox is one of the earliest widespread flowers of the spring. Other names were the Full Sprouting Grass Moon, the Egg Moon and – among coastal tribes – the Full Fish Moon, when the shad come upstream to spawn.

In 2011, this is also the Paschal Full Moon; the first full moon of the spring season. The first Sunday following the Paschal Moon is Easter Sunday, which indeed will be observed one week later on Sunday, April 24. This, incidentally, is just one day shy of the latest date that Easter can fall.

May 17, 7:09 a.m. EDT – Full Flower Moon: Flowers are now abundant everywhere. This moon was also known as the Full Corn Planting Moon or the Milk Moon.

Jun. 15, 4:14 p.m. EDT – Full Strawberry Moon: Strawberry picking season peaks during this month. Europeans called this the Rose Moon. There will be also be a total lunar eclipse that will be visible across much of South America, Europe, Africa and Asia. Totality will last an unusually long length of time: 1 hour 40 minutes.

Jul. 15, 2:40 a.m. EDT – Full Buck Moon: when the new antlers of buck deer push out from their foreheads in coatings of velvety fur. It was also often called the Full Thunder Moon, thunderstorms being now most frequent. Sometimes it's also called the Full Hay Moon.

Aug. 13, 2:57 p.m. EDT – Full Sturgeon Moon: When this large fish of the Great Lakes and other major bodies of water like Lake Champlain is most readily caught. A few tribes knew it as the Full Red Moon because when the moon rises it looks reddish through sultry haze, or the Green Corn Moon or Grain Moon.

The occurrence of this full moon on this particular date is rather poor timing for those who enjoy the annual performance of the Perseid meteor shower; this display will peak on this very same day and the brilliant light of the moon will likely wash out all but the very brightest of these swift streaks of light.

Sep. 12, 5:27 a.m. EDT – Full Harvest Moon: Traditionally, this designation goes to the full moon that occurs closest to the autumnal (fall) equinox. The Harvest Moon usually comes in September in the Northern Hemisphere, but (on average) once or twice a decade it will fall in early October.

At the peak of the harvest, farmers can work into the night by the light of this moon. Usually the moon rises an average of 50 minutes later each night, but for the few nights around the Harvest Moon, the moon seems to rise at nearly the same time each night – just 25 to 30 minutes later across the U.S., and only 10 to 20 minutes later for much of Canada and Europe. Corn, pumpkins, squash, beans and wild rice – the chief Indian staples – are now ready for gathering.

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Messenger findings may 'revolutionize' views of Mercury

2011-09-30T01:47:00.000-07:00

A spacecraft sent to the least explored rocky planet in the solar system is providing surprising new information that may rewrite what scientists believe about the growth of planets.

Mercury, the tiny planet closest to the sun, has a lopsided magnetic field, much more sulfur than expected and strange "hollows" across its surface that may hint at present-day geologic activity, according to data gleaned by the Messenger spacecraft.

The results, published in a package of seven papers in Friday's edition of the journal Science, may force scientists to throw out many ideas about how Mercury formed.

When Mariner 10 flew by in 1974 and 1975, planetary scientists got a tantalizing glimpse at Mercury's moon-like features — craters, flat plains of ancient lava — and discovered it had a magnetic field. The Messenger mission, armed with a suite of instruments including cameras, element-sensing spectrometers and a magnetic field detector, was designed to answer questions dangled by that decades-old snapshot.

Launched in 2004, the spacecraft flew by the planet three times before entering orbit in March of this year, when it sent the first close-up images back to Earth. It will continue to send data as it circles the planet for about a year.

Mercury, planetary scientists knew, is uncommonly dense — most likely because its inner core of iron is very large relative to the rest of the planet. This led some scientists to theorize that Mercury had once been perhaps two to three times larger and its outer layers had been stripped away, either from the sun's fierce glare or major impacts from asteroids.

As molten balls of rock coalesce to form a planet, the heavier elements such as iron tend to sink toward the center while lighter elements such as sulfur or phosphorus, which are more likely to evaporate, drift in the opposite direction. This, scientists had reasoned, would make those volatile lighter elements the first to get stripped away, leaving the planet comparatively dense.

But when scientists used Messenger's gamma-ray and X-ray spectrometers to analyze elements on Mercury's surface, they found that the planet was rich in phosphorus and that sulfur was 10 times more abundant on the surface than on the Earth or moon.

"At this point, the origin of Mercury's large core is still a mystery," said Larry Nittler, a cosmochemist at the Carnegie Institution of Washington who led the X-ray spectrometer study.

Another paper found that the vast flat plains on Mercury were not caused by eruptions from volcanoes but were fashioned from large amounts of lava that seeped up from cracks in the ground and flooded the surface. The scorching-hot lava also carved teardrop-shaped islands into the surface, which are visible near the edges of these plains.

Mercury is "essentially wallpapered by huge volumes of lava," said James Head, a planetary geoscientist at Brown University and lead author of that study.

"Volcanism is important because it represents the pulse of the planets," he added. "It's like the blood of the interior: Is it not doing much inside, or is it really active?"

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"Dark" Supermoon Tomorrow: New Moon Gets Closest to Earth

2011-09-28T05:04:00.001-07:00

Tomorrow night the new moon will make a close approach to Earth, giving rise to the second supermoon of the year—but this one will have the power of invisibility.

Because the moon's orbit is egg shaped, there are times in the roughly monthlong lunar cycle when the moon is at perigee—its closest distance to Earth—or at apogee, its farthest distance from Earth.

"A supermoon occurs when the moon is at perigee and it's in either a full or new phase," said Raminder Singh Samra, an astronomer at the H.R. MacMillan Space Centre in Vancouver, Canada.

In March sky-watchers were treated to a full moon at perigee, which made for the biggest full moon seen in 18 years.

A new moon happens when the lunar orb positions itself between Earth and the sun, so that the side of the moon that faces Earth is unlighted.

"The upcoming moon on September 27, 2011, is set to be at perigee and at the new phase," Samra said, "so we won't be able to witness the event, as the moon and sun will be in the same region of the sky" and the lunar disk will be entirely dark.

Supermoon to Affect Earth's Tides?

Because the size of the moon's orbit also varies slightly, each perigee is not always the same distance from Earth.

When at perigee, the moon is about 18,640 miles (30,000 kilometers) closer to Earth than its average distance of roughly 240,000 miles (385,000 kilometers). When perigee occurs during a full moon, the lunar disk can appear about 14 percent bigger in the sky, Samra said.

Tuesday's dark supermoon will be just 222,175 miles (357,557 kilometers) away from Earth.

Some people have speculated that this lunar proximity can have unusual gravitational effects on Earth, triggering dramatic events such as earthquakes.

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How Common Are Earth-Moon Planetary Systems

2011-09-25T22:39:00.000-07:00

Earth's Moon might have played an important role in the development and evolution of life on Earth. The Moon was formed via a giant impact in which a Mars-size projectile collided with the young Earth. The ejected material accumulated in orbit around our planet and formed the Moon. After its formation, the Moon was much closer to Earth than it is today, which caused high tides several times per day.

This may have helped promote the very early evolution of life. In addition, a stable climate of more than a billion years may be essential to guarantee a suitable environment for life. But without its satellite, Earth would suffer chaotic variations of the direction of its spin axis, which would in turn result in dramatic variations of the climate.

Therefore, concerning the habitability of extrasolar planets, it is reasonable to ask: How common are Earth-Moon planetary systems?

Sebastian Elser, Prof. Ben Moore and Dr. Joachim Stadel of the University of Zurich, Switzerland, along with Ryuji Morishima of NASA's Jet Propulsion Laboratory in Pasadena, California, ran a large set of N-body simulations to study the formation of the rocky planets in our solar system via the collisional growth of thousands of small rocky bodies in a disk around the Sun.

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Plenty of room on planet Earth

2011-09-23T04:42:00.000-07:00

The world now has almost seven billion people and rising. The population may surpass nine billion by 2050. We, together with our 20 billion chickens and four billion cattle, sheep and pigs, will utterly dominate the planet. Can the planet take it? Can we take it?

Yes. Not only is such a huge population going to prove indefinitely "sustainable;" it is actually likely that the ecological impact of nine billion in 2050 will be lighter, not heavier: there will be less pollution and more space left over for nature than there is today.

Consider three startling facts. The world population quadrupled in the 20th century, but the calories available per person went up, not down. The world population doubled in the second half of the century, but the total forest area on the planet went up slightly, not down. The world population increased by a billion in the last 13 years, but the number living in absolute poverty (less than a dollar a day, adjusted for inflation) fell by around a third.

Clearly it is possible at least for a while to escape the fate forecast by Robert Malthus, the pessimistic mathematical cleric, in 1798. We've been proving Malthus wrong for more than 200 years. And now the population explosion is fading. Fertility rates are falling all over the world: in Bangladesh it's down from 6.8 children per woman in 1955 to 2.7 today; China - 5.6 to 1.7; Iran - 7 to 1.7; Nigeria - 6.5 to 5.2; Brazil 6.1 to 1.8; Yemen - 8.3 to 5.1.

The rate of growth of world population has halved since the 1960s; the absolute number added to the population each year has been falling for more than 20 years. According to the United Nations, population will probably cease growing by 2070. This miraculous collapse of fertility has not been caused by Malthusian misery or coercion (except in China), but by the opposite: enrichment, urbanization, female emancipation, education and above all the defeat of child mortality - which means women start to plan families rather than continue breeding.

Increasing prosperity means eating more food, though. Can we really feed today's let alone tomorrow's billions? In 60 years we have trebled the total harvest of the three biggest crops: wheat, rice and corn. Yet the acreage devoted to growing these crops has barely changed. This is because fertilizer, irrigation, pesticides and new varieties have greatly increased yields.

They continue to do so. Growth regulators boost the yield of wheat. Genetic modification boosts the yield of cotton (while increasing the biodiversity in fields). New enzymes promise to cut the phosphate output and increase weight gain of pigs. These technologies save rainforest by sparing land from the plow. If we went back to organic farming, the world would have to cultivate more than twice as much land as we do.

Already huge swaths of the world are being released from farming and reforested. New England is now 80 per cent woodland, where it was once 70 per cent farmland. Italy and England have more woodland than they have for centuries. Moose, coyotes, beavers and bears are back in places where they have not been for centuries. France has a wolf problem; Scotland a deer problem. It is the poor countries, not the affluent ones, that are losing forest. Haiti, with its near total dependence on renewable power (wood), is 98 per cent deforested and counting.

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Our solar system might have once had an extra gas planet

2011-09-20T23:28:00.000-07:00

This solar system just doesn't work. According to a new computer simulation, the planets could never have come together in their current configuration. The only explanation is that we once had a fifth gas giant...and it's still out there somewhere.

That's a pretty big claim to make, so let's see how David Nesvorny of Colorado's Southwest Research Institute reached that particular conclusion. The key idea here is that our solar system wouldn't have formed in its present configuration — the planets would have tugged on each other as they formed, pulling each other out of their original orbits and into new ones. The solar system doesn't begin fully-formed, even once the various planets are complete. It's still a long evolutionary process.

We can't know exactly how the planets first fit together, so Nesvorny simply tried a bunch of different possible starting positions and ran simulations to find out which could conceivably result in the present solar system. The problem is that Jupiter, Saturn, Uranus, and Neptune are just so damn big that they can barely move around without violently disrupting each other's orbits.

In the vast majority of simulations, one gas giant would rip another apart. Even in simulations where all four gas giants survived, it was often at the expense of the rocky planets. According to Nesvorny's simulation, the current solar system is of astoundingly low probability, assuming we're only starting with four inner rocky planets and four outer gas planets. It's when you alter that assumption that things start to get interesting.

By adding a fifth gas planet into the mix, Nesvorny found that the odds of our current solar system emerging increased dramatically. That's obviously not proof of this fifth gas planet's existence, but if this computer simulation holds up, then it's actually more likely than not.

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Fifty New Exoplanets Discovered by HARPS

2011-09-19T01:24:00.000-07:00

Astronomers using ESO’s world-leading exoplanet hunter HARPS have today announced a rich haul of more than 50 new exoplanets, including 16 super-Earths, one of which orbits at the edge of the habitable zone of its star. By studying the properties of all the HARPS planets found so far, the team has found that about 40% of stars similar to the Sun have at least one planet lighter than Saturn.

The HARPS spectrograph on the 3.6-metre telescope at ESO’s La Silla Observatory in Chile is the world’s most successful planet finder [1]. The HARPS team, led by Michel Mayor (University of Geneva, Switzerland), today announced the discovery of more than 50 new exoplanets orbiting nearby stars, including sixteen super-Earths [2]. This is the largest number of such planets ever announced at one time [3]. The new findings are being presented at a conference on Extreme Solar Systems where 350 exoplanet experts are meeting in Wyoming, USA.

“The harvest of discoveries from HARPS has exceeded all expectations and includes an exceptionally rich population of super-Earths and Neptune-type planets hosted by stars very similar to our Sun. And even better — the new results show that the pace of discovery is accelerating,” says Mayor.

In the eight years since it started surveying stars like the Sun using the radial velocity technique HARPS has been used to discover more than 150 new planets. About two thirds of all the known exoplanets with masses less than that of Neptune [4] were discovered by HARPS. These exceptional results are the fruit of several hundred nights of HARPS observations [5].

Working with HARPS observations of 376 Sun-like stars, astronomers have now also much improved the estimate of how likely it is that a star like the Sun is host to low-mass planets (as opposed to gaseous giants). They find that about 40% of such stars have at least one planet less massive than Saturn. The majority of exoplanets of Neptune mass or less appear to be in systems with multiple planets.

With upgrades to both hardware and software systems in progress, HARPS is being pushed to the next level of stability and sensitivity to search for rocky planets that could support life. Ten nearby stars similar to the Sun were selected for a new survey. These stars had already been observed by HARPS and are known to be suitable for extremely precise radial velocity measurements. After two years of work, the team of astronomers has discovered five new planets with masses less than five times that of Earth.

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16 'super-Earths' found outside solar system

2011-09-13T22:37:00.000-07:00

It's not like aliens put up a welcome banner or anything, but scientists now have newly identified at least one planet that could potentially sustain life.

The European Southern Observatory has just announced the discovery of more than 50 new exoplanets (planets outside our solar system), including 16 super-Earths (planets whose mass is between one and 10 times that of our own planet).

One of these planets in particular could theoretically be home to life if conditions are right. It's called HD 85512 b, and scientists say it's about 3.6 times the mass of the Earth. This planet is about 35 light years from Earth. Its location with respect to its star suggests that this planet could have liquid water under certain circumstances.

Don't get too excited, though; there's a lot more work to be done to explore whether this planet is truly fit for life, in addition to whether there are alien life forms there.

The discovery comes from High Accuracy Radial Velocity Planet Searcher, or HARPS. HARPS is located at the La Silla Observatory in Chile, and is part of a telescope that's nearly 12 feet long.

Here's how it works, according to ESO: When a planet orbits a star, the star move towards and away from the person who's stargazing on Earth in a regular fashion. That's called a change in radial velocity. Because of the Doppler effect, changes in radial velocity makes the star's light spectrum move towards longer wavelengths when it's moving away, and towards shorter wavelengths as it gets closer. HARPS can detect this shift in the spectrum, and infer that there is a planet present.

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Solar system with Earth-size planet found

2011-07-17T22:23:00.000-07:00

After six years of painstaking observations, astronomers have identified a distant solar system with at least five Neptune-class worlds orbiting within 130 million miles or so of the parent star--closer than Mars is to the sun. Two other planets are believed to be present, including one just 1.4 times as massive as Earth.

The presumed Earth-size planet orbits a scant 2 million miles from its star, completing a full orbit, or "year," every 1.18 days. If confirmed with additional observations, this hellish world would be the smallest yet discovered, additional proof that Earth-size planets are falling within the reach of current Earth-based instruments.

"We have probably found the system with the most planets known today, coming close to the solar system," Christophe Lovis of the University of Geneva, lead author of a paper reporting the discovery, told CNET in an e-mail exchange. "This means that we are now able to detect very complex systems of low-mass planets, which will help us a lot [in] understanding their diversity. This a step towards answering long-standing questions, such as, how common are habitable planets in the universe?"

As for the presumed Earth-size planet, Lovis said "it is probable that such a low-mass body cannot retain an atmosphere so close to its star. Most likely, this body is like a big melted-lava ball. Hard to imagine, since this is unknown in our solar system."

Over six years, Lovis and his colleagues used a sensitive spectrograph mounted on the European Southern Observatory's 3.6-meter (11.8-foot) telescope at La Silla, Chile, to measure subtle changes in the light from a sun-like star known as HD 10180 in the southern constellation Hydrus.

Located 127 light-years from Earth, HD 10180 wobbles ever so slightly, as it is tugged this way and that by the gravity of a retinue of unseen planets. Over the course of 190 observations, astronomers were able to confirm the presence of at least five Neptune-like planets between 13 and 25 times as massive as Earth.

All five worlds orbit HD 10180 at distances ranging from 0.06 and 1.4 times the distance between the Earth and the sun, out to about 130 million miles. The much smaller, yet-to-be-confirmed planet orbits inside the five Neptune-class worlds. A seventh Saturn-class planet is believed to be at a range of 3.4 times the Earth-sun distance, taking six Earth years to complete one orbit.

According to the Extrasolar Planets Encyclopaedia maintained by the Paris Observatory, 488 planets beyond Earth's solar system have been discovered to date. Some 15 solar systems feature at least three planets. A star known as 55 Cancri has five confirmed planets, including two Jupiter-class worlds.

The HD 10180 solar system is unique in that its planets circle the parent star in nearly circular orbits and seem to be positioned according to a relatively simple arithmetic rule that may be "a consequence of the various gravitational interactions that occur between the planets during their evolution," Lovis said.

"It is difficult to say at this point how significant this result is, but it will be very interesting to hear what our theoretician colleagues think of it," he added.

Surprisingly, perhaps, it appears the HD 10180 solar system is gravitationally stable over long time scales, despite the effects of five Neptune-class planets orbiting so close to their star.

"This was not an easy question, and answering it required in-depth dynamical analyses," Lovis said. "When modeling all major effects properly (including effects of general relativity), it turns out that the system is indeed stable over long time scales."

He said additional observations will be needed to pin down the orbit and mass of the innermost, Earth-class planet.

"We will dedicate some more telescope nights to observe the star...to improve the coverage of the 1.18-day period," he said of the smaller planet. "At the moment, we are suffering from the fact that we take one single data point per night, which makes it difficult to be sure about a 1.18-day period. I expect that we will make progress on this system within a year or so."

The observations are extremely difficult. The gravitational tug of the low-mass planet amounts to a 1.8 mph wobble in a star 127 light-years away, "which is hard to measure and, if confirmed, would represent a new record in precision," Lovis said.

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Dawn Team Members Check out Spacecraft

2011-07-12T20:26:00.001-07:00

Dawn Mission Status Update

Mission managers for NASA's Dawn spacecraft are studying the spacecraft's ion propulsion system after Dawn experienced a loss of thrust on June 27. Dawn team members were able to trace the episode to an electronic circuit in the spacecraft's digital control and interface unit, a subsystem that houses the circuit and a computer that provides the "brains" to Dawn's ion propulsion system. That circuit appeared to lose an electronic signal. As a result, the valves controlling the flow of xenon fuel did not open properly. Dawn automatically put itself into a more basic configuration known as "safe-communications" mode, where the spacecraft stopped some activities and turned its high-gain antenna to Earth.

Engineers were able to return the spacecraft to a normal configuration and restart the spacecraft's thrusting on June 30 by switching to a second digital control and interface unit with equivalent capabilities. One set of images for navigation purposes was not obtained on June 28 because the spacecraft was in safe-communications mode, and one other set, on July 6, was not obtained to allow the spacecraft to spend the time thrusting. Other sets of navigation images have been and will be acquired as expected. The ion propulsion system is now functioning normally.

"Dawn is still on track to get into orbit around Vesta, and thanks to the flexibility provided by our use of ion propulsion, the time of orbit capture actually will move earlier by a little less than a day," said Marc Rayman, Dawn's chief engineer and mission manager. "More importantly, the rest of Dawn's schedule is unaffected, and science collection is expected to begin as scheduled in early August."

In an unrelated event, the visible and infrared mapping spectrometer on Dawn reset itself on June 29. At the time of the reset, the instrument was gathering calibration data during the spacecraft's approach to the giant asteroid Vesta. Some of its planned observations were completed successfully before automatic sensors turned the instrument off.

On June 30, Dawn team members were able to trace the reset to an internal error in the instrument's central processing unit, though they don't yet know why the internal error occurred. By temporarily turning the instrument back on, the Dawn team confirmed that the instrument is otherwise in a normal configuration. They powered the instrument back off, as originally planned for this time. Team members are working to determine when they will turn it back on again.

After arriving at Vesta, Dawn will spend about one year orbiting the asteroid, which is also known as a protoplanet because it is a large body that almost became a planet. Data collected at Vesta will help scientists understand the earliest chapter of our solar system's history.

The Dawn mission to Vesta and Ceres is managed by the Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. The University of California, Los Angeles, is responsible for overall Dawn mission science. Other scientific partners include Planetary Science Institute, Tucson, Ariz.; Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany; DLR Institute for Planetary Research, Berlin, Germany; Italian National Institute for Astrophysics, Rome; and the Italian Space Agency, Rome. Orbital Sciences Corporation of Dulles, Va., designed and built the Dawn spacecraft.

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NASA's Spitzer Finds Distant Galaxies Grazed on Gas

2011-07-01T03:39:00.000-07:00

PASADENA, Calif. -- Galaxies once thought of as voracious tigers are more like grazing cows, according to a new study using NASA's Spitzer Space Telescope.

Astronomers have discovered that galaxies in the distant, early universe continuously ingested their star-making fuel over long periods of time. This goes against previous theories that the galaxies devoured their fuel in quick bursts after run-ins with other galaxies.

"Our study shows the merging of massive galaxies was not the dominant method of galaxy growth in the distant universe," said Ranga-Ram Chary of NASA's Spitzer Science Center at the California Institute of Technology in Pasadena, Calif. "We're finding this type of galactic cannibalism was rare. Instead, we are seeing evidence for a mechanism of galaxy growth in which a typical galaxy fed itself through a steady stream of gas, making stars at a much faster rate than previously thought."

Chary is the principal investigator of the research, appearing in the Aug. 1 issue of the Astrophysical Journal. According to his findings, these grazing galaxies fed steadily over periods of hundreds of millions of years and created an unusual amount of plump stars, up to 100 times the mass of our sun.

"This is the first time that we have identified galaxies that supersized themselves by grazing," said Hyunjin Shim, also of the Spitzer Science Center and lead author of the paper. "They have many more massive stars than our Milky Way galaxy."

Galaxies like our Milky Way are giant collections of stars, gas and dust. They grow in size by feeding off gas and converting it to new stars. A long-standing question in astronomy is: Where did distant galaxies that formed billions of years ago acquire this stellar fuel? The most favored theory was that galaxies grew by merging with other galaxies, feeding off gas stirred up in the collisions.

Chary and his team addressed this question by using Spitzer to survey more than 70 remote galaxies that existed 1 to 2 billion years after the Big Bang (our universe is approximately 13.7 billion years old). To their surprise, these galaxies were blazing with what is called H alpha, which is radiation from hydrogen gas that has been hit with ultraviolet light from stars. High levels of H alpha indicate stars are forming vigorously. Seventy percent of the surveyed galaxies show strong signs of H alpha. By contrast, only 0.1 percent of galaxies in our local universe possess this signature.

Previous studies using ultraviolet-light telescopes found about six times less star formation than Spitzer, which sees infrared light. Scientists think this may be due to large amounts of obscuring dust, through which infrared light can sneak. Spitzer opened a new window onto the galaxies by taking very long-exposure infrared images of a patch of sky called the GOODS fields, for Great Observatories Origins Deep Survey.

Further analyses showed that these galaxies furiously formed stars up to 100 times faster than the current star-formation rate of our Milky Way. What's more, the star formation took place over a long period of time, hundreds of millions of years. This tells astronomers that the galaxies did not grow due to mergers, or collisions, which happen on shorter timescales. While such smash-ups are common in the universe -- for example, our Milky Way will merge with the Andromeda galaxy in about 5 billion years -- the new study shows that large mergers were not the main cause of galaxy growth. Instead, the results show that distant, giant galaxies bulked up by feeding off a steady supply of gas that probably streamed in from filaments of dark matter.

Chary said, "If you could visit a planet in one of these galaxies, the sky would be a crazy place, with tons of bright stars, and fairly frequent supernova explosions."

NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the Spitzer Space Telescope mission for the agency's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech. Caltech manages JPL for NASA.

New Animation Depicts Next Mars Rover in Action

2011-06-25T01:14:00.001-07:00

Although NASA's Mars Science Laboratory will not leave Earth until late this year nor land on Mars until August 2012, anyone can watch those dramatic events now in a new animation of the mission.

The full, 11-minute animation shows sequences such as the spacecraft separating from its launch vehicle near Earth and the mission's rover, Curiosity, zapping rocks with a laser and examining samples of powdered rock on Mars.

Curiosity's landing will use a different method than any previous Mars landing, with the rover suspended on tethers from a rocket-backpack "sky crane."

The new animation combines detailed views of the spacecraft with scenes of real places on Mars, based on stereo images taken by earlier missions.

"It is a treat for the 2,000 or more people who have worked on the Mars Science Laboratory during the past eight years to watch these action scenes of the hardware the project has developed and assembled," said Mars Science Laboratory Project Manager Pete Theisinger at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The animation also provides an exciting view of this mission for any fan of adventure and exploration."

JPL manages the Mars Science Laboratory project for the NASA Science Mission Directorate, Washington. The rover and other parts of the spacecraft have been delivered to NASA Kennedy Space Center in Florida for launch during the period of Nov. 25 to Dec. 18, 2011. In August 2012, Curiosity will land on Mars for a two-year mission to examine whether conditions in the landing area have been favorable for microbial life and for preserving evidence about whether life has existed there. JPL is a division of the California Institute of Technology, Pasadena.

NASA SAYS SUN AND PLANETS CONSTRUCTED DIFFERENTLY

2011-06-23T22:59:00.000-07:00

PASADENA, Calif. - Researchers analyzing samples returned by NASA's 2004 Genesis mission have discovered that our sun and its inner planets may have formed differently than previously thought.

Data revealed differences between the sun and planets in oxygen and nitrogen, which are two of the most abundant elements in our solar system. Although the difference is slight, the implications could help determine how our solar system evolved.

"We found that Earth, the moon, as well as Martian and other meteorites which are samples of asteroids, have a lower concentration of the O-16 than does the sun," said Kevin McKeegan, a Genesis co-investigator from UCLA, and the lead author of one of two Science papers published this week. "The implication is that we did not form out of the same solar nebula materials that created the sun -- just how and why remains to be discovered."

The air on Earth contains three different kinds of oxygen atoms which are differentiated by the number of neutrons they contain. Nearly 100 percent of oxygen atoms in the solar system are composed of O-16, but there are also tiny amounts of more exotic oxygen isotopes called O-17 and O-18. Researchers studying the oxygen of Genesis samples found that the percentage of O-16 in the sun is slightly higher than on Earth or on other terrestrial planets. The other isotopes' percentages were slightly lower.

Another paper detailed differences between the sun and planets in the element nitrogen. Like oxygen, nitrogen has one isotope, N-14, that makes up nearly 100 percent of the atoms in the solar system, but there is also a tiny amount of N-15. Researchers studying the same samples saw that when compared to Earth's atmosphere, nitrogen in the sun and Jupiter has slightly more N-14, but 40 percent less N-15. Both the sun and Jupiter appear to have the same nitrogen composition. As is the case for oxygen, Earth and the rest of the inner solar system are very different in nitrogen.

"These findings show that all solar system objects including the terrestrial planets, meteorites and comets are anomalous compared to the initial composition of the nebula from which the solar system formed," said Bernard Marty, a Genesis co-investigator from Centre de Recherches Pétrographiques et Géochimiques and the lead author of the other new Science paper. "Understanding the cause of such a heterogeneity will impact our view on the formation of the solar system."

Data were obtained from analysis of samples Genesis collected from the solar wind, or material ejected from the outer portion of the sun. This material can be thought of as a fossil of our nebula because the preponderance of scientific evidence suggests that the outer layer of our sun has not changed measurably for billions of years.

"The sun houses more than 99 percent of the material currently in our solar system, so it's a good idea to get to know it better," said Genesis Principal Investigator Don Burnett of the California Institute of Technology, Pasadena, Calif. "While it was more challenging than expected, we have answered some important questions, and like all successful missions, generated plenty more."

Genesis launched in August 2000. The spacecraft traveled to Earth's L1 Lagrange Point about 1 million miles from Earth, where it remained for 886 days between 2001 and 2004, passively collecting solar-wind samples.

On Sept. 8, 2004, the spacecraft released a sample return capsule, which entered Earth's atmosphere. Although the capsule made a hard landing as a result of a failed parachute in the Utah Test and Training Range in Dugway, Utah, it marked NASA's first sample return since the final Apollo lunar mission in 1972, and the first material collected beyond the moon. NASA's Johnson Space Center in Houston curates the samples and supports analysis and sample allocation.

The Jet Propulsion Laboratory, Pasadena, Calif., managed the Genesis mission for NASA's Science Mission Directorate, Washington. The Genesis mission was part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems, Denver, developed and operated the spacecraft. Analysis at the Centre de Recherches Pétrographiques et Géochimiques, Nancy, France, was supported by the Centre National d'Etudes Spatiales, Paris, and the Centre National de la Recherche Scientifique, Paris, France.

Astronomers Find Newly Discovered Asteroid Is Earth's Companion

2011-05-09T22:15:00.000-07:00

Astronomers from the Armagh Observatory in Northern Ireland have found that a recently discovered asteroid has been following Earth in its motion around the Sun for at least the past 250,000 years, and may be intimately related to the origin of our planet.

The asteroid first caught the eye of the scientists, Apostolos "Tolis" Christou and David Asher, two months after it was found by the WISE infrared survey satellite, launched in 2009 by the United States. "Its average distance from the Sun is identical to that of the Earth,", "but what really impressed me at the time was how Earth-like its orbit was." Most near-Earth Asteroids -- NEAs for short -- have very eccentric, or egg-shaped, orbits that take the asteroid right through the inner solar system. But the new object, designated 2010 SO16, is different. Its orbit is almost circular so that it cannot come close to any other planet in the solar system except Earth.

The researchers set out to investigate how stable this orbit is and how long the asteroid has occupied it. To do that, they first had to take into account the current uncertainty in the asteroid's orbit. "Not knowing precisely the location of a newly-discovered NEA is quite common," explained Dr Asher. "The only way to eliminate the uncertainty is to keep tracking the asteroid for as long as possible, usually months or years." But the two scientists overcame that problem by creating virtual "clones" of the asteroid for every possible orbit that it could conceivably occupy. They then simulated the evolution of these clones under the gravity of the Sun and the planets for two million years into the past and in the future.

Comet Elenin: Preview of a Coming Attraction

2011-05-08T21:43:00.000-07:00

Comet Elenin, was first detected on Dec. 10, 2010 by Leonid Elenin, an observer in Lyubertsy, Russia, who made the discovery "remotely" using the ISON-NM observatory near Mayhill, New Mexico. At the time of the discovery, the comet was about 647 million kilometers from Earth. Over the past four-and-a-half months, the comet has - as comets do - closed the distance to Earth's vicinity as it makes its way closer to perihelion. As of May 4, Elenin's distance is about 274 million kilometers.

"That is what happens with these long-period comets that come in from way outside our planetary system," said Don Yeomans of NASA's Near-Earth Object Program Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "They make these long, majestic, speedy arcs through our solar system, and sometimes they put on a great show. But not Elenin. Right now that comet looks kind of wimpy."

Mars Express Sees Deep Fractures on Mars

2011-05-06T20:53:00.000-07:00

Newly released images from the European Space Agency's Mars Express show Nili Fossae, a system of deep fractures around the giant Isidis impact basin. Some of these incisions into the martian crust are up to 500 m deep and probably formed at the same time as the basin.

Nili Fossae is a 'graben' system on Mars, northeast of the Syrtis Major volcanic province, on the northwestern edge of the giant Isidis impact basin. Graben refers to the lowered terrain between two parallel faults or fractures in the rocks that collapses when tectonic forces pull the area apart. The Nili Fossae system contains numerous graben concentrically oriented around the edges of the basin.

It is thought that flooding of the basin with basaltic lava after the impact that created it resulted in subsidence of the basin floor, adding stress to the planet's crust, which was released by the formation of the fractures.

A strongly eroded impact crater is visible to the bottom right of the image. It measures about 12 km across and exhibits an ejecta blanket, usually formed by material thrown out during the impact. Two landslides have taken place to the west of the crater. Whether they were a direct result of the impact or occurred later is unknown.

Mars Tribute Marks Memories of Shepard's Flight

2011-05-05T21:28:00.000-07:00

The team exploring Mars via NASA's Opportunity rover for the past seven years has informally named a Martian crater for the Mercury spacecraft that astronaut Alan Shepard christened Freedom 7. On May 5, 1961, Shepard piloted Freedom 7 in America's first human spaceflight.

The team is using Opportunity this week to acquire images covering a cluster of small, relatively young craters along the rover's route toward a long-term destination. The cluster's largest crater, spanning about 25 meters , is the one called "Freedom 7." The diameter of Freedom 7 crater, about 25 meters, happens to be equivalent to the height of the Redstone rocket that launched Shepard's flight.

"Many of the people currently involved with the robotic investigations of Mars were first inspired by the astronauts of the Mercury Project who paved the way for the exploration of our solar system," said Scott McLennan of the State University of New York at Stony Brook, who is this week's long-term planning leader for the rover science team. Shepard's flight was the first of six Project Mercury missions piloted by solo astronauts.

Dawn Reaches Milestone Approaching Asteroid Vesta

2011-05-03T21:12:00.000-07:00

NASA's Dawn spacecraft has reached its official approach phase to the asteroid Vesta and will begin using cameras for the first time to aid navigation for an expected July 16 orbital encounter. The large asteroid is known as a protoplanet – a celestial body that almost formed into a planet.

At the start of this three-month final approach to this massive body in the asteroid belt, Dawn is 1.21 million kilometers (752,000 miles) from Vesta, or about three times the distance between Earth and the moon. During the approach phase, the spacecraft's main activity will be thrusting with a special, hyper-efficient ion engine that uses electricity to ionize and accelerate xenon. The 12-inch-wide ion thrusters provide less thrust than conventional engines, but will provide propulsion for years during the mission and provide far greater capability to change velocity. "We feel a little like Columbus approaching the shores of the New World," said Christopher Russell, Dawn principal investigator, based at the University of California in Los Angeles (UCLA). "The Dawn team can't wait to start mapping this Terra Incognita."

Plasmoids and Sheaths Mean Success or Failure for Solar Eruptions

2011-05-02T23:09:00.000-07:00

Our Sun experiences regular eruptions of material into space, but solar physicists still have difficulty in explaining why these dramatic events take place. Now a group of scientists from the University of St Andrews think they have the answer: clouds of plasma constrained by magnetic fields and known as 'plasmoids' that struggle to break free of the Sun's magnetic field.

Active regions on the solar surface are often the site of eruptions. These are associated with magnetic fields from the solar interior rising to the surface and gradually expanding into the Sun's outer atmosphere, the corona, in a process known as magnetic flux emergence. The St Andrews team developed 3D computer models of these phenomena, revealing that the emergence of magnetic flux naturally leads to the formation and expulsion of plasmoids that adopt a twisted tube configuration.

NASA's Swift and Hubble Probe Asteroid Collision Debris

2011-04-29T22:25:00.000-07:00

Data from NASA's Swift satellite and Hubble Space Telescope showed these changes likely occurred after Scheila was struck by a much smaller asteroid. "Collisions between asteroids create rock fragments, from fine dust to huge boulders, that impact planets and their moons," said Dennis Bodewits, an astronomer at the University of Maryland in College Park and lead author of the Swift study. "Yet this is the first time we've been able to catch one just weeks after the smash-up, long before the evidence fades away."

Asteroids are rocky fragments thought to be debris from the formation and evolution of the solar system approximately 4.6 billion years ago. Millions of them orbit the sun between Mars and Jupiter in the main asteroid belt. Scheila is approximately 70 miles across and orbits the sun every five years."The Hubble data are most simply explained by the impact, at 11,000 mph, of a previously unknown asteroid about 100 feet in diameter," said Hubble team leader David Jewitt at the University of California in Los Angeles. Hubble did not see any discrete collision fragments, unlike its 2009 observations of P/2010 A2, the first identified asteroid collision.

Voyager Probes Set to Enter Interstellar Space

2011-04-28T20:56:00.000-07:00

NASA's twin Voyager probes are now at the edge of the solar system. Not only that, they're still working. And with each passing day they are beaming back a message that, to scientists, is both unsettling and thrilling. "It's uncanny," says Ed Stone of the California Institute of Technology in Pasadena, Voyager Project Scientist since 1972. "Voyager 1 and 2 have a knack for making discoveries." Today, April 28, 2011, NASA held a live briefing to reflect on what the Voyager mission has accomplished--and to preview what lies ahead as the probes prepare to enter the realm of interstellar space in our Milky Way galaxy.

The adventure began in the late 1970s when the probes took advantage of a rare alignment of outer planets for an unprecedented Grand Tour. Voyager 1 visited Jupiter and Saturn, while Voyager 2 flew past Jupiter, Saturn, Uranus and Neptune.

Austrian Space Forum Successfully Tests Mars Suit ‘Aouda.X’ in Spain

2011-04-26T20:43:00.000-07:00

A team from the Austrian Space Forum is arriving back in Austria April 25, 2011 following a week testing its analogue space suit 'Aouda.X' in the semi-desert of Rio Tinto in Spain. This suit has been developed by the Austrian Space Forum over three years and is one of the best models of its kind worldwide.

The European Space Agency (ESA) also participated in this mission with the Mars rover 'Eurobot'. This 1.5 million Euro prototype was been transported from the Netherlands to Spain and passed its first test under field conditions on April 19. Valuable scientific and technical data have been collected between during the tests, which ran from April 18 to 21. Aouda.X and Eurobot completed several activities together, demonstrating it was possible to test the man-machine-interface, which will play a vital role in a real Mars mission.

Huge Dry Ice Deposit on Mars: NASA Orbiter Reveals Big Changes in Red Planet's Atmosphere

2011-04-21T21:12:00.000-07:00

NASA's Mars Reconnaissance Orbiter has discovered the total amount of atmosphere on Mars changes dramatically as the tilt of the planet's axis varies. This process can affect the stability of liquid water, if it exists on the Martian surface, and increase the frequency and severity of Martian dust storms.

Researchers using the orbiter's ground-penetrating radar identified a large, buried deposit of frozen carbon dioxide, or dry ice, at the Red Planet's south pole. The scientists suspect that much of this carbon dioxide enters the planet's atmosphere and swells the atmosphere's mass when Mars' tilt increases. The findings are published in the journal Science.

The newly found deposit has a volume similar to Lake Superior's nearly 3,000 cubic miles. The deposit holds up to 80 percent as much carbon dioxide as today's Martian atmosphere. Collapse pits caused by dry ice sublimation and other clues suggest the deposit is in a dissipating phase, adding gas to the atmosphere each year. Mars' atmosphere is about 95 percent carbon dioxide, in contrast to Earth's much thicker atmosphere, which is less than .04 percent carbon dioxide.

Beams of Electrons Link Saturn With Its Moon Enceladus

2011-04-20T20:51:00.000-07:00

Data from NASA's Cassini spacecraft have revealed that Enceladus, one of Saturn's diminutive moons, is linked to Saturn by powerful electrical currents -- beams of electrons that flow back and forth between the planet and moon. one of the instruments on board Cassini which made the electron beam discovery, includes a electron sensor called CAPS-ELS -- led by UCL (University College London).

Since Cassini's arrival at Saturn in 2004 it has passed 500km-wide Enceladus 14 times, gradually discovering more of its secrets on each visit. Research has found that jets of gas and icy grains emanate from the south pole of Enceladus, which become electrically charged and form an ionosphere. The motion of Enceladus and its ionosphere through the magnetic bubble that surrounds Saturn acts like a dynamo, setting up the newly-discovered current system.

Astronomers Can Tune in to Radio Auroras to Find Exoplanets

2011-04-19T20:45:00.000-07:00

scientists at the University of Leicester have shown that emissions from the radio aurora of planets like Jupiter should be detectable by radio telescopes such as LOFAR, which will be completed later this year. Dr Jonathan Nichols will present results at the RAS National Astronomy Meeting in Llandudno, Wales, on April 18.

"This is the first study to predict the radio emissions by exoplanetary systems similar to those we find at Jupiter or Saturn. At both planets, we see radio waves associated with auroras generated by interactions with ionised gas escaping from the volcanic moons, Io and Enceladus. Our study shows that we could detect emissions from radio auroras from Jupiter-like systems orbiting at distances as far out as Pluto," said Nichols.

Of the hundreds of exoplanets that have been detected to date, less than 10% orbit at distances where we find the outer planets in our own Solar System. Most exoplanets have been found by the transit method, which detects a dimming in light as a planet moves in front of a star, or by looking for a wobble as a star is tugged by the gravity of an orbiting planet. With both these techniques, it is easiest to detect planets close in to the star and moving very quickly.

Solar Activity Heats Up: Sunspots Finally Return

2011-04-15T20:54:00.000-07:00

If you've ever stood in front of a hot stove, watching a pot of water and waiting impatiently for it to boil, you know what it feels like to be a solar physicist. Back in 2008, the solar cycle plunged into the deepest minimum in nearly a century. Sunspots all but vanished, solar flares subsided, and the sun was eerily quiet.

"Ever since, we've been waiting for solar activity to pick up," says Richard Fisher, head of the Heliophysics Division at NASA Headquarters in Washington DC. "It's been three long years." Quiet spells on the sun are nothing new. They come along every 11 years or so, it's a natural part of the solar cycle. This particular solar minimum, however, was lasting longer than usual, prompting some researchers to wonder if it would ever end.

Fast-Rotating Asteroid Winks For Astronomer's Camera

2011-04-14T21:29:00.000-07:00

Video imaging of newly discovered asteroid 2011 GP59 shows the object appearing to blink on and off about once every four minutes. Amateur astronomers, including Nick James of Chelmsford, Essex, England, have captured video of the interesting object. James generated this video of GP59 on the night of Monday, April 11. The video, captured with an 11-inch Schmidt-Cassegrain telescope, is a compilation of 137 individual frames, each requiring 30 seconds of exposure. At the time, the asteroid was approximately 3,356,000 kilometers distant.

"Usually, when we see an asteroid strobe on and off like that, it means that the body is elongated and we are viewing it broadside along its long axis first, and then on its narrow end as it rotates ," said Don Yeomans, manager of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif. "GP59 is approximately 50 meters [240 feet] long, and we think its period of rotation is about seven-and-a-half minutes. This makes the object's brightness change every four minutes or so." 2011 GP59 was discovered the night of April 8/9 by astronomers with the Observatorio Astronomico de Mallorca in Andalusia, Spain. It will make its closest approach to Earth on April 15 at 19:09 UTC (12:09 p.m. PDT) at a distance just beyond the moon's orbit - about 533,000 kilometers.

Mars Rover's 'Gagarin' Moment Applauded Exploration

2011-04-12T20:45:00.001-07:00

A flat, light-toned rock on Mars visited by NASA's Mars Exploration Rover in 2005 informally bears the name of the first human in space, Yuri Gagarin, who rode into orbit in the Soviet Union's Vostok-1 spacecraft on April 12, 1961. The team using Opportunity to explore the Meridiani Planum region of Mars since 2004 chose "Gagarin" for what they would call the rock that the rover examined beside "Vostok" crater. A target for close-up examination on Gagarin is called "Yuri." To commemorate Gagarin's flight, a color image of the rock on Mars has been posted, here. The image combines frames taken through three different filters by Opportunity's panoramic camera. Early accomplishments in the Space Age inspired many of the researchers exploring other planets robotically today, who hope their work can, in turn, help inspire the next generation.

"The 50th anniversary of mankind's first fledgling foray into the cosmos should serve as an important reminder of the spirit of adventure and exploration that has propelled mankind throughout history," said Mars rover science team member James Rice of NASA Goddard Space Flight Center, Greenbelt, Md. "We are a species of explorers; it is encoded into our very DNA. Half a century ago Yuri Gagarin was lofted into a totally unknown, remote and hostile environment and in doing so opened up a new limitless frontier of possibilities for mankind. A mere 23 days later another brave human, Alan Shepard, climbed aboard a rocket and ventured into the starry abyss. Their courage and vision continue to inspire and lead us into the unknown. Hopefully, one day in the not too distant future it will lead humanity on a voyage to Mars."

Saturn's Moon Titan Shaped by Weather, Not Ice Volcanoes?

2011-04-11T23:08:00.000-07:00

Have the surface and belly of Saturn's smog-shrouded moon, Titan, recently simmered like a chilly, bubbling cauldron with ice volcanoes, or has this distant moon gone cold? In a newly published analysis, a pair of NASA scientists analyzing data collected by the Cassini spacecraft suggests Titan may be much less geologically active than some scientists have thought.

"It would be fantastic to find strong evidence that clearly shows Titan has an internal heat source that causes ice volcanoes and lava flows to form," said Jeff Moore, lead author of the paper and a planetary scientist at NASA's Ames Research Center, Moffett Field, Calif. "But we find that the evidence presented to date is unconvincing, and recent studies of Titan's interior conducted by geophysicists and gravity experts also weaken the possibility of volcanoes there."

NASA's Jupiter-Bound Spacecraft Arrives in Florida

2011-04-10T22:16:00.000-07:00

NASA's Juno spacecraft has arrived in Florida to begin final preparations for a launch this summer. The spacecraft was shipped from Lockheed Martin Space Systems, Denver, to the Astrotech payload processing facility in Titusville, Fla., today. The solar-powered Juno spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere. "The Juno spacecraft and the team have come a long way since this project was first conceived in 2003," said Scott Bolton, Juno's principal investigator, based at Southwest Research Institute in San Antonio. "We're only a few months away from a mission of discovery that could very well rewrite the books on not only how Jupiter was born, but how our solar system came into being."

Next Monday, Juno will be removed from its shipping container, the first of the numerous milestones to prepare it for launch. Later that week, the spacecraft will begin functional testing to verify its state of health after the road trip from Colorado. After this, the team will load updated flight software and perform a series of mission readiness tests. These tests involve the entire spacecraft flight system, as well as the associated science instruments and the ground data system.

NASA's Next Mars Rover Nears Completion

2011-04-06T21:30:00.000-07:00

Assembly and testing of NASA's Mars Science Laboratory spacecraft is far enough along that the mission's rover, Curiosity, looks very much as it will when it is investigating Mars. Testing continues this month at NASA's Jet Propulsion Laboratory, Pasadena, Calif., on the rover and other components of the spacecraft that will deliver Curiosity to Mars. In May and June, the spacecraft will be shipped to NASA Kennedy Space Center, Fla., where preparations will continue for launch in the period between Nov. 25 and Dec. 18, 2011.

The mission will use Curiosity to study one of the most intriguing places on Mars - still to be selected from among four finalist landing-site candidates. It will study whether a selected area of Mars has offered environmental conditions favorable for microbial life and for preserving evidence about whether Martian life has existed. JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Science Laboratory mission for the NASA Science Mission Directorate, Washington.

Forensic Sleuthing Ties Ring Ripples to Impacts-NASA's Information

2011-03-31T21:54:00.000-07:00

scientists working with data from NASA's Cassini, Galileo and New Horizons missions have traced telltale ripples in the rings of Saturn and Jupiter back to collisions with cometary fragments dating back more than 10 years ago. The ripple-producing culprit, in the case of Jupiter, was comet Shoemaker-Levy 9, whose debris cloud hurtled through the thin Jupiter ring system during a kamikaze course into the planet in July 1994. Scientists attribute Saturn's ripples to a similar object – likely another cloud of comet debris -- plunging through the inner rings in the second half of 1983. The findings are detailed in a pair of papers published online today in the journal Science.

"What's cool is we're finding evidence that a planet's rings can be affected by specific, traceable events that happened in the last 30 years, rather than a hundred million years ago," said Matthew Hedman, a Cassini imaging team associate, lead author of one of the papers, and a research associate at Cornell University, Ithaca, N.Y. "The solar system is a much more dynamic place than we gave it credit for." From Galileo's visit to Jupiter, scientists have known since the late 1990s about patchy patterns in the Jovian ring. But the Galileo images were a little fuzzy, and scientists didn't understand why such patterns would occur. The trail was cold until Cassini entered orbit around Saturn in 2004 and started sending back thousands of images. A 2007 paper by Hedman and colleagues first noted corrugations in Saturn's innermost ring, dubbed the D ring.

When is an Asteroid Not an Asteroid?

2011-03-30T20:53:00.000-07:00

German astronomer Heinrich Wilhelm Olbers spotted Vesta as a pinprick of light in the sky. Two hundred and four years later, as NASA's Dawn spacecraft prepares to begin orbiting this intriguing world, scientists now know how special this world is, even if there has been some debate on how to classify it. Vesta is most commonly called an asteroid because it lies in the orbiting rubble patch known as the main asteroid belt between Mars and Jupiter. But the vast majority of objects in the main belt are lightweights, 100-kilometers-wide (about 60-miles wide) or smaller, compared with Vesta, which is about 530 kilometers (330 miles) across on average. In fact, numerous bits of Vesta ejected by collisions with other objects have been identified in the main belt.

"I don't think Vesta should be called an asteroid," said Tom McCord, a Dawn co-investigator based at the Bear Fight Institute, Winthrop, Wash. "Not only is Vesta so much larger, but it's an evolved object, unlike most things we call asteroids." The layered structure of Vesta is the key trait that makes Vesta more like planets such as Earth, Venus and Mars than the other asteroids, McCord said. Like the planets, Vesta had sufficient radioactive material inside when it coalesced, releasing heat that melted rock and enabled lighter layers to float to the outside. Scientists call this process differentiation.

Work Stopped on Alternative Cameras for Mars Rover

2011-03-29T21:05:00.000-07:00

NASA rover to be launched to Mars this year will carry the Mast Camera instrument already on the vehicle, providing the capability to meet the mission's science goals. Work has stopped on an alternative version of the instrument, with a pair of zoom-lens cameras, which would have provided additional capabilities for improved three-dimensional video. The installed Mastcam on the Mars Science Laboratory mission's Curiosity rover uses two fixed-focal-length cameras: a telephoto for one eye and wider angle for the other. Malin Space Science Systems, San Diego, built the Mastcam and was funded by NASA last year to see whether a zoom version could be developed in time for testing on Curiosity.

"With the Mastcam that was installed last year and the rover's other instruments, Curiosity can accomplish its ambitious research goals," said Mars Science Laboratory Project Scientist John Grotzinger, of the California Institute of Technology, Pasadena. "Malin Space Science Systems has provided excellent, unprecedented science cameras for this mission. The possibility for a zoom-camera upgrade was very much worth pursuing, but time became too short for the levels of testing that would be needed for them to confidently replace the existing cameras. We applaud Malin Space Science Systems for their tremendous effort to deliver the zooms, and also the Mars Science Laboratory Project's investment in supporting this effort." Malin Space Science Systems has also provided the Mars Hand Lens Imager and the Mars Descent Imager instruments on Curiosity. The company will continue to pursue development of the zoom system, both to prove out the design and to make the hardware available for possible use on future missions.

NASA Stardust Spacecraft Officially Ends Operations

2011-03-27T21:21:00.000-07:00

NASA's Stardust spacecraft sent its last transmission to Earth at 4:33 p.m. PDT (7:33 p.m. EDT) Thursday, March 24, shortly after depleting fuel and ceasing operations. During a 12-year period, the venerable spacecraft collected and returned comet material to Earth and was reused after the end of its prime mission in 2006 to observe and study another comet during February 2011.

The Stardust team performed the burn to depletion because the comet hunter was literally running on fumes. The depletion maneuver command was sent from the Stardust-NExT mission control area at Lockheed Martin Space Systems in Denver. The operation was designed to fire Stardust's rockets until no fuel remained in the tank or fuel lines. The spacecraft sent acknowledgment of its last command from approximately 312 million kilometers (194 million miles) away in space. "This is the end of the spacecraft's operations, but really just the beginnings of what this spacecraft's accomplishments will give to planetary science," said Lindley Johnson, Stardust-NExT and Discovery program executive at NASA Headquarters in Washington. "The treasure-trove of science data and engineering information collected and returned by Stardust is invaluable for planning future deep space planetary missions."

After completion of the burn, mission personnel began comparing the computed amount of fuel consumed during the engine firing with the anticipated amount based on consumption models. The models are required to track fuel levels, because there are no fully reliable fuel gauges for spacecraft in the weightless environment of space. Mission planners use approximate fuel usage by reviewing the history of the vehicle's flight, how many times and how long its rocket motors fired.

NASA's Venerable Comet Hunter Wraps up Mission

2011-03-24T23:45:00.000-07:00

At 33 minutes after 4 p.m. PDT on 24-3-2011, NASA's Stardust spacecraft finished its last transmission to Earth. The transmission came on the heels of the venerable spacecraft's final rocket burn, which was designed to provide insight into how much fuel remained aboard after its encounter with comet Tempel 1 in February. "Stardust has been teaching us about our solar system since it was launched in 1999," said Stardust-NExT project manager Tim Larson from NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It makes sense that its very last moments would be providing us with data we can use to plan deep space mission operations in the future."

The burn to depletion maneuver was designed to fire Stardust's rockets until insufficient fuel remains to continue, all the while downlinking data on the burn to Earth some 312 million kilometers (194 million miles) away. Mission personnel will compare the amount of fuel consumed in the burn with the amount they anticipated would be burned based on their fuel consumption models. Fuel consumption models are necessary because no one has invented a reliable fuel gauge for spacecraft when in the weightless environment of space flight. Until that day arrives, mission planners can approximate fuel usage by looking at the history of the vehicle's flight and how many times and for how long its rocket motors have fired. Mission personnel watched the final data from the burn come down at JPL's Space Flight Operations Facility and at the Stardust-NExT mission support center at Lockheed Martin Space Systems in Denver.

NASA's Stardust: Good to the Last Drop

2011-03-24T01:48:00.000-07:00

On Thursday, March 24 at about 4 p.m. PDT (7 p.m. EDT), NASA's Stardust spacecraft will perform a final burn with its main engines.

At first glance, the burn is something of an insignificant event. After all, the venerable spacecraft has executed 40 major flight path maneuvers since its 1999 launch, and between these main engines and the reaction control system, its rocket motors have collectively fired more than 2 million times. But the March 24 burn will be different from all others. This burn will effectively end the life of NASA's most traveled comet hunter.

"We call it a 'burn to depletion,' and that is pretty much what we're doing – firing our rockets until there is nothing left in the tank," said Stardust-NExT project manager Tim Larson of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It's a unique way for an interplanetary spacecraft to go out. Essentially, Stardust will be providing us useful information to the very end."

Burn to depletion will answer the question about how much fuel Stardust had left in its tank. "We'll take those data and compare them to what our estimates told us was left," said Allan Cheuvront, Lockheed Martin Space Systems program manager for Stardust-NExT. "That will give us a better idea how valid our fuel consumption models are and make our predictions even more accurate for future missions."

Next Mars Rover Gets a Test Taste of Mars Conditions

2011-03-22T04:07:00.000-07:00

A space-simulation chamber at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is temporary home this month for the Curiosity rover, which will land on Mars next year.
Tests inside the 25-foot-diameter chamber (7.6-meters) are putting the rover through various sequences in environmental conditions resembling Martian surface conditions. After the chamber's large door was sealed last week, air was pumped out to near-vacuum pressure, liquid nitrogen in the walls dropped the temperature to minus 130 degrees Celsius (minus 202 degrees Fahrenheit), and a bank of powerful lamps simulated the intensity of sunshine on Mars.

Other portions of NASA's Mars Science Laboratory spacecraft, including the cruise stage, descent stage and backshell, remain in JPL's Spacecraft Assembly Facility, where Curiosity was assembled and where the rover will return after the simulation-chamber tests. In coming months, those flight system components and the rover will be shipped to NASA's Kennedy Space Center in Florida for final preparations before the launch period of Nov. 25 to Dec. 18, 2011.

The mission will use Curiosity to study one of the most intriguing places on Mars -- still to be selected from among four finalist landing-site candidates. It will study whether a selected area of Mars has offered environmental conditions favorable for microbial life and for preserving evidence about whether Martian life has existed.
JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Science Laboratory mission for the NASA Science Mission Directorate, Washington.

MESSENGER Begins Historic Orbit Around Mercury

2011-03-18T01:42:00.000-07:00

NASA’s MESSENGER spacecraft successfully achieved orbit around Mercury at approximately 9 p.m. EDT Thursday. This marks the first time a spacecraft has accomplished this engineering and scientific milestone at our solar system's innermost planet.

For the next several weeks, APL engineers will be focused on ensuring the spacecraft’s systems are all working well in Mercury’s harsh thermal environment. Starting on March 23, the instruments will be turned on and checked out, and on April 4 the mission's primary science phase will begin.

Prolific NASA Orbiter Reaches Five-Year Mark

2011-03-17T01:49:00.000-07:00

NASA's versatile Mars Reconnaissance Orbiter, which began orbiting Mars five years ago on March 10, has radically expanded our knowledge of the Red Planet and is now working overtime.

The mission has provided copious information about ancient environments, ice-age-scale climate cycles and present-day changes on Mars.

The orbiter observes Mars' surface, subsurface and atmosphere in unprecedented detail. The spacecraft's large solar panels and dish antenna have enabled it to transmit more data to Earth -- 131 terabits and counting, including more than 70,000 images -- than all other interplanetary missions combined. Yet many things had to go well for the mission to achieve these milestones.

After a seven-month journey from Earth, the spacecraft fired its six main engines for nearly 27 minutes as it approached Mars on March 10, 2006. Mars could not capture it into orbit without this critically timed maneuver to slow the spacecraft. The orbiter's intended path took it behind Mars, out of communication, during most of the engine burn.

Waiter, There's Metal in My Moon Water

2011-02-21T22:37:00.000-08:00

Bring a filter if you plan on drinking water from the moon. Water ice recently discovered in dust at the bottom of a crater near the moon's south pole is accompanied by metallic elements like mercury, magnesium, calcium, and even a bit of silver. Now you can add sodium to the mix, according to Dr. Rosemary Killen of NASA's Goddard Space Flight Center in Greenbelt, Md.

Recent discoveries of significant deposits of water on the moon were surprising because our moon has had a tough life. Intense asteroid bombardments in its youth, coupled with its weak gravity and the Sun's powerful radiation, have left the moon with almost no atmosphere. This rendered the lunar surface barren and dry, compared to Earth.

However, due to the moon's orientation to the Sun, scientists theorized that deep craters at the lunar poles would be in permanent shadow and thus extremely cold, and able to trap volatile material like water as ice if such material were somehow transported there, perhaps by comet impacts or chemical reactions with hydrogen, a major component of the solar wind.

Can WISE Find the Hypothetical 'Tyche'?

2011-02-18T21:25:00.000-08:00

In November 2010, the scientific journal Icarus published a paper by astrophysicists John Matese and Daniel Whitmire, who proposed the existence of a binary companion to our sun, larger than Jupiter, in the long-hypothesized "Oort cloud" -- a faraway repository of small icy bodies at the edge of our solar system. The researchers use the name "Tyche" for the hypothetical planet. Their paper argues that evidence for the planet would have been recorded by the Wide-field Infrared Survey Explorer (WISE).

WISE is a NASA mission, launched in December 2009, which scanned the entire celestial sky at four infrared wavelengths about 1.5 times. It captured more than 2.7 million images of objects in space, ranging from faraway galaxies to asteroids and comets relatively close to Earth. Recently, WISE completed an extended mission, allowing it to finish a complete scan of the asteroid belt, and two complete scans of the more distant universe, in two infrared bands. So far, the mission's discoveries of previously unknown objects include an ultra-cold star or brown dwarf, 20 comets, 134 near-Earth objects (NEOs), and more than 33,000 asteroids in the main belt between Mars and Jupiter.

Following its successful survey, WISE was put into hibernation in February 2011. Analysis of WISE data continues. A preliminary public release of the first 14 weeks of data is planned for April 2011, and the final release of the full survey is planned for March 2012.

Catching Space Weather in the Act

2011-02-18T06:31:00.000-08:00

Close to the globe, Earth's magnetic field wraps around the planet like a gigantic spherical web, curving in to touch Earth at the poles. But this isn't true as you get further from the planet. As you move to the high altitudes where satellites fly, nothing about that field is so simple. Instead, the large region enclosed by Earth's magnetic field, known as the magnetosphere, looks like a long, sideways jellyfish with its round bulb facing the sun and a long tail extending away from the sun.

In the center of that magnetic tail lies the plasma sheet. Here, strange things can happen. Magnetic field lines pull apart and come back together, creating explosions when they release energy. Disconnected bits of the tail called "plasmoids" get ejected into space at two million miles per hour. And legions of charged particles flow back toward Earth.

Such space weather events cause auroras and, when very strong, can produce radiation events that could cause our satellites to fail. But until now no one has been able to take pictures of these fascinating processes in the plasma sheet.

NASA Releases Images of Man-Made Crater on Comet

2011-02-17T04:45:00.000-08:00

NASA's Stardust spacecraft returned new images of a comet showing a scar resulting from the 2005 Deep Impact mission. The images also showed the comet has a fragile and weak nucleus.

The spacecraft made its closest approach to comet Tempel 1 on Monday, Feb. 14, at 8:40 p.m. PST (11:40 p.m. EST) at a distance of approximately 178 kilometers (111 miles). Stardust took 72 high-resolution images of the comet. It also accumulated 468 kilobytes of data about the dust in its coma, the cloud that is a comet's atmosphere. The craft is on its second mission of exploration called Stardust-NExT, having completed its prime mission collecting cometary particles and returning them to Earth in 2006.

The Stardust-NExT mission met its goals, which included observing surface features that changed in areas previously seen during the 2005 Deep Impact mission; imaging new terrain; and viewing the crater generated when the 2005 mission propelled an impactor at the comet.

Comet Hunter's First Images on the Ground

2011-02-15T22:58:00.000-08:00

Mission controllers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., have begun receiving the first of 72 anticipated images of comet Tempel 1 taken by NASA's Stardust spacecraft.

The first six, most distant approach images are available at http://www.nasa.gov/stardust and http://www.jpl.nasa.gov. Additional images, including those from closest approach, are being downlinked in chronological order and will be available later in the day.

A news conference will be held at 12:30 p.m. PST (3:30 p.m. EST) to allow scientists more time to analyze the data and images.

Stardust-NExT is a low-cost mission that expands on the investigation of comet Tempel 1 initiated by NASA's Deep Impact spacecraft. JPL, a division of the California Institute of Technology in Pasadena, manages Stardust-NExT for NASA's Science Mission Directorate, Washington, D.C. Joe Veverka of Cornell University, Ithaca, N.Y., is the mission's principal investigator. Lockheed Martin Space Systems, Denver, built the spacecraft and manages day-to-day mission operations.

NASA Spacecraft Hours From Comet Encounter

2011-02-14T21:40:00.000-08:00

As of today, Feb. 14, at 9:21 a.m. PST (12:21 p.m. EST), NASA's Stardust-NExT mission spacecraft is within a quarter-million miles (402,336 kilometers) of its quarry, comet Tempel 1, which it will fly by tonight. The spacecraft is cutting the distance with the comet at a rate of about 10.9 kilometers per second (6.77 miles per second or 24,000 mph).

The flyby of Tempel 1 will give scientists an opportunity to look for changes on the comet's surface since it was visited by NASA's Deep Impact spacecraft in July 2005. Since then, Tempel 1 has completed one orbit of the sun, and scientists are looking forward to discovering any differences in the comet.

The closest approach is expected tonight at approximately 8:40 p.m. PST (11:40 p.m. EST).

During the encounter phase, the spacecraft will carry out many important milestones in short order and automatically, as the spacecraft is too far away to receive timely updates from Earth. These milestones include turning the spacecraft to point its protective shields between it and the anticipated direction from which cometary particles would approach. Another milestone will occur at about four minutes to closest approach, when the spacecraft will begin science imaging of the comet's nucleus.

SDO Celebrates One Year Anniversary

2011-02-13T22:27:00.000-08:00

On February 11, 2010, at 10:23 in the morning, NASA's Solar Dynamics Observatory (SDO) launched into space on an Atlas rocket from Cape Canaveral. A year later, SDO has sent back millions of stunning images of the sun and a host of new data to help us understand the complex star at the heart of our solar system.

"One of the highlights of the last year is just that everything worked so smoothly," says astrophysicist Dean Pesnell, the project scientist for SDO at NASA's Goddard Space Flight Center in Greenbelt, Md. "We turned it on in March and it immediately started sending us data at 150 megabits per second. It worked from the very get go."

New View of Family Life in the North American Nebula

2011-02-10T21:47:00.000-08:00

Stars at all stages of development, from dusty little tots to young adults, are on display in a new image from NASA's Spitzer Space Telescope.

This cosmic community is called the North American nebula. In visible light, the region resembles the North American continent, with the most striking resemblance being the Gulf of Mexico. But in Spitzer's infrared view, the continent disappears. Instead, a swirling landscape of dust and young stars comes into view.

"One of the things that makes me so excited about this image is how different it is from the visible image, and how much more we can see in the infrared than in the visible," said Luisa Rebull of NASA's Spitzer Science Center at the California Institute of Technology, Pasadena, Calif. Rebull is lead author of a paper about the observations, accepted for publication in the Astrophysical Journal Supplement Series. "The Spitzer image reveals a wealth of detail about the dust and the young stars here."

Heading Into the Bonus Round – in Space

2011-02-10T00:59:00.000-08:00

NASA's Stardust spacecraft was launched on Feb. 7, 1999, on a mission that would explore a comet as no previous mission had. Before Stardust, seven spacecraft from NASA, Russia, Japan and the European Space Agency had visited comets – they had flight profiles that allowed them to perform brief encounters, collecting data and sometimes images of the nuclei during the flyby.

Like those comet hunters before it, Stardust was tasked to pass closely by a comet, collecting data and snapping images. It also had the ability to come home again, carrying with it an out-of -this-world gift for cometary scientists – particles of the comet itself. Along the way, the telephone booth-sized comet hunter racked up numerous milestones and more than a few "space firsts."

NASA Hosting Events for Valentine's Night Comet Encounter

2011-02-08T22:36:00.001-08:00

NASA will host several live activities for the Stardust-NExT mission's close encounter with comet Tempel 1. The closest approach is expected at approximately 8:37 p.m. PST (11:37 p.m. EST) on Feb. 14, with confirmation received on Earth at about 8:56 p.m. PST (11:56 p.m. EST).

Live coverage of the Tempel 1 encounter will begin at 8:30 p.m. PST on Feb. 14 on NASA Television and the agency's website. The coverage will include live commentary from mission control at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and video from Lockheed Martin Space System's mission support area in Denver.

LRO Could Have Given Apollo 14 Crew Another Majestic View

2011-02-08T01:04:00.000-08:00

Although the Apollo 14 mission to the moon was filled with incredible sights and was completely successful it met all its science goals the crew experienced a bit of a disappointment at missing the spectacular view from the rim of a 1,000-foot-wide crater. They might have gazed into its depths if they had the high-resolution maps now available from NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft.

Pressure was on the Apollo 14 mission, launched January 31, 1971, from the start. The Apollo 13 landing had to be aborted because an oxygen tank explosion crippled the spacecraft as it was on its way to the moon. It was a heroic effort just to return the crew safely to Earth, but the Apollo 14 team knew a second failure would probably result in cancellation of the remaining Apollo missions.

First Ever STEREO Images of the Entire Sun

2011-02-07T00:33:00.001-08:00

On Feb. 6th, NASA's twin STEREO probes moved into position on opposite sides of the sun, and they are now beaming back uninterrupted images of the entire star—front and back.

"For the first time ever, we can watch solar activity in its full 3-dimensional glory," says Angelos Vourlidas, a member of the STEREO science team at the Naval Research Lab in Washington, DC.

"This is a big moment in solar physics," says Vourlidas. "STEREO has revealed the sun as it really is--a sphere of hot plasma and intricately woven magnetic fields."

Each STEREO probe photographs half of the star and beams the images to Earth. Researchers combine the two views to create a sphere. These aren't just regular pictures, however. STEREO's telescopes are tuned to four wavelengths of extreme ultraviolet radiation selected to trace key aspects of solar activity such as flares, tsunamis and magnetic filaments. Nothing escapes their attention.

Surprise Hidden in Titan's Smog: Cirrus-Like Clouds

2011-02-03T22:12:00.000-08:00

Every day is a bad-air day on Saturn's largest moon, Titan. Blanketed by haze far worse than any smog belched out in Los Angeles, Beijing or even Sherlock Holmes's London, the moon looks like a dirty orange ball. Described once as crude oil without the sulfur, the haze is made of tiny droplets of hydrocarbons with other, more noxious chemicals mixed in. Gunk.

Icky as it may sound, Titan is really the rarest of gems: the only moon in our solar system with an atmosphere worthy of a planet. This atmosphere comes complete with lightning, drizzle and occasionally a big, summer-downpour style of cloud made of methane or ethane -- hydrocarbons that are best known for their role in natural gas.

Now, thin, wispy clouds of ice particles, similar to Earth's cirrus clouds, are being reported by Carrie Anderson and Robert Samuelson at NASA's Goddard Space Flight Center in Greenbelt, Md. The findings, published February 1 in Icarus, were made using the Composite Infrared Spectrometer (CIRS) on NASA's Cassini spacecraft.

NASA's Kepler Spacecraft Discovers Extraordinary New Planetary System

2011-02-02T23:19:00.001-08:00

Scientists using NASA's Kepler, a space telescope, recently discovered six planets made of a mix of rock and gases orbiting a single sun-like star, known as Kepler-11, which is located approximately 2,000 light years from Earth.

"The Kepler-11 planetary system is amazing," said Jack Lissauer, a planetary scientist and a Kepler science team member at NASA's Ames Research Center, Moffett Field, Calif. "It’s amazingly compact, it’s amazingly flat, there’s an amazingly large number of big planets orbiting close to their star - we didn’t know such systems could even exist."

In other words, Kepler-11 has the fullest, most compact planetary system yet discovered beyond our own.

"Few stars are known to have more than one transiting planet, and Kepler-11 is the first known star to have more than three," said Lissauer. "So we know that systems like this are not common. There’s certainly far fewer than one percent of stars that have systems like Kepler-11. But whether it’s one in a thousand, one in ten thousand or one in a million, that we don’t know, because we only have observed one of them."

Cassini Sends Back Postcards of Saturn Moons

2011-02-02T01:14:00.000-08:00

On Jan. 31, 2011, NASA's Cassini spacecraft passed by several of Saturn's intriguing moons, snapping images along the way. Cassini passed within about 60,000 kilometers (37,282 miles) of Enceladus and 28,000 kilometers (17,398 miles) of Helene. It also caught a glimpse of Mimas in front of Saturn's rings. In one of the images, Cassini is looking at the famous jets erupting from the south polar terrain of Enceladus.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute in Boulder, Colo.

Tracking the Origins of Speedy Space Particles

2011-02-01T02:31:00.000-08:00

NASA's Time History of Events and Macroscale Interaction during Substorms (THEMIS) spacecraft combined with computer models have helped track the origin of the energetic particles in Earth's magnetic atmosphere that appear during a kind of space weather called a substorm. Understanding the source of such particles and how they are shuttled through Earth's atmosphere is crucial to better understanding the Sun's complex space weather system and thus protect satellites or even humans in space.

The results show that these speedy electrons gain extra energy from changing magnetic fields far from the origin of the substorm that causes them. THEMIS, which consists of five orbiting satellites, helped provide these insights when three of the spacecraft traveled through a large substorm on February 15, 2008. This allowed scientists to track changes in particle energy over a large distance. The observations were consistent with numerical models showing an increase in energy due to changing magnetic fields, a process known as betatron acceleration.

"The origin of fast electrons in substorms has been a puzzle," says Maha Ashour-Abdalla, the lead author of a Nature Physics paper that appeared online on January 30, 2011 on the subject and a physicist at the University of California, Los Angeles. "It hasn't been clear until now if they got their burst of speed in the middle of the storm, or from some place further away."

NASA Comet Hunter Spots Its Valentine

2011-01-30T22:09:00.000-08:00

NASA's Stardust spacecraft has downlinked its first images of comet Tempel 1, the target of a flyby planned for Valentine's Day, Feb. 14. The images were taken on Jan. 18 and 19 from a distance of 26.3 million kilometers (16.3 million miles), and 25.4 million kilometers (15.8 million miles) respectively. On Feb. 14, Stardust will fly within about 200 kilometers (124 miles) of the comet's nucleus.

"This is the first of many images to come of comet Tempel 1," said Joe Veverka, principal investigator of NASA's Stardust-NExT mission from Cornell University, Ithaca, N.Y. "Encountering something as small and fast as a comet in the vastness of space is always a challenge, but we are very pleased with how things are setting up for our Valentine's Day flyby."

The composite image is a combination of several images taken by Stardust's navigation camera. Future images will be used to help mission navigators refine Stardust's trajectory, or flight path, as it closes the distance between comet and spacecraft at a rate of about 950,000 kilometers (590,000 miles) a day. On the night of encounter, the navigation camera will be used to acquire 72 high-resolution images of the comet's surface features. Stardust-NExT mission scientists will use these images to see how surface features on comet Tempel 1 have changed over the past five-and-a-half years. (Tempel 1 had previously been visited and imaged in July of 2005 by NASA's Deep Impact mission).

Asteroids Ahoy! Jupiter Scar Likely from Rocky Body

2011-01-27T22:20:00.000-08:00

A hurtling asteroid about the size of the Titanic caused the scar that appeared in Jupiter's atmosphere on July 19, 2009, according to two papers published recently in the journal Icarus.

Data from three infrared telescopes enabled scientists to observe the warm atmospheric temperatures and unique chemical conditions associated with the impact debris. By piecing together signatures of the gases and dark debris produced by the impact shockwaves, an international team of scientists was able to deduce that the object was more likely a rocky asteroid than an icy comet. Among the teams were those led by Glenn Orton, an astronomer at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and Leigh Fletcher, researcher at Oxford University, U.K., who started the work while he was a postdoctoral fellow at JPL.

"Both the fact that the impact itself happened at all and the implication that it may well have been an asteroid rather than a comet shows us that the outer solar system is a complex, violent and dynamic place, and that many surprises may be out there waiting for us," said Orton. "There is still a lot to sort out in the outer solar system."

NASA's Hubble Finds Most Distant Galaxy Candidate Ever Seen in Universe

2011-01-27T00:01:00.000-08:00

Astronomers have pushed NASA's Hubble Space Telescope to its limits by finding what is likely to be the most distant object ever seen in the universe. The object's light traveled 13.2 billion years to reach Hubble, roughly 150 million years longer than the previous record holder. The age of the universe is approximately 13.7 billion years.

The tiny, dim object is a compact galaxy of blue stars that existed 480 million years after the big bang. More than 100 such mini-galaxies would be needed to make up our Milky Way. The new research offers surprising evidence that the rate of star birth in the early universe grew dramatically, increasing by about a factor of 10 from 480 million years to 650 million years after the big bang.

Runaway Star Plows Through Space

2011-01-24T21:53:00.000-08:00

A massive star flung away from its former companion is plowing through space dust. The result is a brilliant bow shock, seen here as a yellow arc in a new image from NASA's Wide-field Infrared Survey Explorer, or WISE.

The star, named Zeta Ophiuchi, is huge, with a mass of about 20 times that of our sun. In this image, in which infrared light has been translated into visible colors we see with our eyes, the star appears as the blue dot inside the bow shock.

Zeta Ophiuchi once orbited around an even heftier star. But when that star exploded in a supernova, Zeta Ophiuchi shot away like a bullet. It's traveling at a whopping 54,000 miles per hour (or 24 kilometers per second), and heading toward the upper left area of the picture.

As the star tears through space, its powerful winds push gas and dust out of its way and into what is called a bow shock. The material in the bow shock is so compressed that it glows with infrared light that WISE can see. The effect is similar to what happens when a boat speeds through water, pushing a wave in front of it.

Voyager Celebrates 25 Years Since Uranus Visit

2011-01-21T21:43:00.000-08:00

As NASA's Voyager 2 spacecraft made the only close approach to date of our mysterious seventh planet Uranus 25 years ago, Project Scientist Ed Stone and the Voyager team gathered at NASA's Jet Propulsion Laboratory, Pasadena, Calif., to pore over the data coming in.

Images of the small, icy Uranus moon Miranda were particularly surprising. Since small moons tend to cool and freeze over rapidly after their formation, scientists had expected a boring, ancient surface, pockmarked by crater-upon-weathered-crater. Instead they saw grooved terrain with linear valleys and ridges cutting through the older terrain and sometimes coming together in chevron shapes. They also saw dramatic fault scarps, or cliffs. All of this indicated that periods of tectonic and thermal activity had rocked Miranda's surface in the past.

The scientists were also shocked by data showing that Uranus's magnetic north and south poles were not closely aligned with the north-south axis of the planet's rotation. Instead, the planet's magnetic field poles were closer to the Uranian equator. This suggested that the material flows in the planet's interior that are generating the magnetic field are closer to the surface of Uranus than the flows inside Earth, Jupiter and Saturn are to their respective surfaces.

Mars Sliding Behind Sun After Rover Anniversary

2011-01-21T01:30:00.000-08:00

The team operating NASA's Mars rover Opportunity will temporarily suspend commanding for 16 days after the rover's seventh anniversary next week, but the rover will stay busy.

For the fourth time since Opportunity landed on Mars on Jan. 25, 2004, Universal Time (Jan. 24, Pacific Time), the planets' orbits will put Mars almost directly behind the sun from Earth's perspective.

During the days surrounding such an alignment, called a solar conjunction, the sun can disrupt radio transmissions between Earth and Mars. To avoid the chance of a command being corrupted by the sun and harming a spacecraft, NASA temporarily refrains from sending commands from Earth to Mars spacecraft in orbit and on the surface. This year, the commanding moratorium will be Jan. 27 to Feb. 11 for Opportunity, with similar periods for the Mars Reconnaissance Orbiter and Mars Odyssey orbiter.

NASA Spacecraft Prepares for Valentine's Day Comet Rendezvous

2011-01-20T06:26:00.001-08:00

NASA's Stardust-NExT spacecraft is nearing a celestial date with comet Tempel 1 at approximately 8:37 p.m. PST (11:37 p.m. EST), on Feb. 14. The mission will allow scientists for the first time to look for changes on a comet's surface that occurred following an orbit around the sun.

The Stardust-NExT, or New Exploration of Tempel, spacecraft will take high-resolution images during the encounter, and attempt to measure the composition, distribution, and flux of dust emitted into the coma, or material surrounding the comet's nucleus. Data from the mission will provide important new information on how Jupiter-family comets evolved and formed.

The mission will expand the investigation of the comet initiated by NASA's Deep Impact mission. In July 2005, the Deep Impact spacecraft delivered an impactor to the surface of Tempel 1 to study its composition. The Stardust spacecraft may capture an image of the crater created by the impactor. This would be an added bonus to the huge amount of data that mission scientists expect to obtain.

More Asteroids Could Have Made Life's Ingredients

2011-01-19T01:31:00.000-08:00

A wider range of asteroids were capable of creating the kind of amino acids used by life on Earth, according to new NASA research.

Amino acids are used to build proteins, which are used by life to make structures like hair and nails, and to speed up or regulate chemical reactions. Amino acids come in two varieties that are mirror images of each other, like your hands. Life on Earth uses the left-handed kind exclusively. Since life based on right-handed amino acids would presumably work fine, scientists are trying to find out why Earth-based life favored left-handed amino acids.

In March, 2009, researchers at NASA's Goddard Space Flight Center in Greenbelt, Md., reported the discovery of an excess of the left-handed form of the amino acid isovaline in samples of meteorites that came from carbon-rich asteroids. This suggests that perhaps left-handed life got its start in space, where conditions in asteroids favored the creation of left-handed amino acids. Meteorite impacts could have supplied this material, enriched in left-handed molecules, to Earth. The bias toward left-handedness would have been perpetuated as this material was incorporated into emerging life.

Holes in the Sun's Corona

2011-01-12T00:12:00.000-08:00

This Solar Dynamics Observatory image of the Sun taken on January 10 in extreme ultraviolet light captures a dark coronal hole just about at sun center. Coronal holes are areas of the Sun's surface that are the source of open magnetic field lines that head way out into space. They are also the source regions of the fast solar wind, which is characterized by a relatively steady speed of approximately 800 km/s (about 1.8 million mph). As the sun continues to rotate, the high speed solar wind particles blowing from this hole will likely reach Earth in a few days and may spark some auroral activity.

Hotspots in Fountains on the Sun's Surface Help Explain Coronal Heating Mystery

2011-01-07T23:28:00.000-08:00

Among the many constantly moving, appearing, disappearing and generally explosive events in the sun's atmosphere, there exist giant plumes of gas -- as wide as a state and as long as Earth -- that zoom up from the sun's surface at 150,000 miles per hour. Known as spicules, these are one of several phenomena known to transfer energy and heat throughout the sun's magnetic atmosphere, or corona.

Thanks to NASA's Solar Dynamics Observatory (SDO) and the Japanese satellite Hinode, these spicules have recently been imaged and measured better than ever before, showing them to contain hotter gas than previously observed. Thus, they may perhaps play a key role in helping to heat the sun's corona to a staggering million degrees or more. (A number made more surprising since the sun's surface itself is only about 10,000 degrees Fahrenheit.)

Hinode Observes Annular Solar Eclipse

2011-01-07T03:11:00.000-08:00

On January 4, the Hinode satellite captured these breathtaking images of an annular solar eclipse. An annular eclipse occurs when the moon, slightly more distant from Earth than on average, moves directly between Earth and the sun, thus appearing slightly smaller to observers' eyes; the effect is a bright ring, or annulus of sunlight, around the silhouette of the moon. Hinode, a Japanese mission in partnership with NASA, NAOJ, STFC, ESA, and NSC, currently in Earth orbit, is studying the Sun to improve our understanding of the mechanisms that power the solar atmosphere and drive solar eruptions.

Rover Will Spend 7th Birthday at Stadium-Size Crater

2011-01-06T01:02:00.000-08:00

The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter captured a Dec. 31, 2010, view of the Mars Exploration Rover Opportunity on the southwestern rim of a football-field-size crater called "Santa Maria."

Opportunity arrived at the western edge of Santa Maria crater in mid-December and will spend about two months investigating rocks there. That investigation will take Opportunity into the beginning of its eighth year on Mars. Opportunity landed in the Meridiani Planum region of Mars on Jan. 25, 2004, Universal Time (Jan. 24, Pacific Time) for a mission originally planned to last for three months.

NASA Checking on Rover Spirit During Martian Spring

2011-01-05T04:55:00.000-08:00

Nine months after last hearing from the Mars rover Spirit, NASA is stepping up efforts to regain communications with the rover before spring ends on southern Mars in mid-March.

Spirit landed on Mars Jan. 4, 2004 (Universal Time; Jan. 3, Pacific Time) for a mission designed to last for three months. After accomplishing its prime-mission goals, Spirit worked for more than five years in bonus-time extended missions.

"The amount of solar energy available for Spirit is still increasing every day for the next few months," said Mars Exploration Rover Project Manager John Callas of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "As long as that's the case, we will do all we can to increase the chances of hearing from the rover again."

After mid-March, prospects for reviving Spirit would begin to drop. Communication strategies would change based on reasoning that Spirit's silence is due to factors beyond just a low-power condition. Mission-ending damage from the cold experienced by Spirit in the past Martian winter is a real possibility.

Bob Benson: Tales of Chilly Research

2010-12-31T00:38:00.000-08:00

As the weather gets colder in Maryland, Bob Benson tells tales of winters he used to know in Minnesota, the South Pole, and Alaska. A five-decade career studying Earth's ionosphere – the part of Earth's atmosphere that reflects radio communication waves – has taken him to some extreme latitudes.

Standing in the corner of Bob Benson's office is a microfilm reader. You know, the big, boxy machine that was used to look up archived newspaper articles before such things were an Internet search away. That machine is one of the tools Benson has used to scan decades worth of data throughout his 46 years at NASA’s Goddard Space Flight Center in Greenbelt, Md. He studies the ionosphere – the swath of our atmosphere filled with electrons and ions stretching from about 30 to 600 miles above Earth's surface – and the data he studied from various ionospheric satellites were displayed on 35-millimeter film.

"We had thousands of these boxes," he says, holding up a small cardboard box in which a film lies curled. "When I first came here, we'd go pull them from a drawer at the National Space Science Data Center at Goddard and do analysis with a machine like this."

Cassini Celebrates 10 Years Since Jupiter Encounter

2010-12-30T02:27:00.000-08:00

Ten years ago, on Dec. 30, 2000, NASA's Cassini spacecraft made its closest approach to Jupiter on its way to orbiting Saturn. The main purpose was to use the gravity of the largest planet in our solar system to slingshot Cassini towards Saturn, its ultimate destination. But the encounter with Jupiter, Saturn's gas-giant big brother, also gave the Cassini project a perfect lab for testing its instruments and evaluating its operations plans for its tour of the ringed planet, which began in 2004.

"The Jupiter flyby allowed the Cassini spacecraft to stretch its wings, rehearsing for its prime time show, orbiting Saturn," said Linda Spilker, Cassini project scientist based at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Ten years later, findings from the Jupiter flyby still continue to shape our understanding of similar processes in the Saturn system."

Cassini spent about six months - from October 2000 to March 2001 - exploring the Jupiter system. The closest approach brought Cassini to within about 9.7 million kilometers (6 million miles) of Jupiter's cloud tops at 2:05 a.m. Pacific Time, or 10:05 a.m. UTC, on Dec. 30, 2000.

SOHO Spots 2000th Comet

2010-12-29T03:13:00.000-08:00

As people on Earth celebrate the holidays and prepare to ring in the New Year, an ESA/NASA spacecraft has quietly reached its own milestone: on December 26, the Solar and Heliospheric Observatory (SOHO) discovered its 2000th comet.

Drawing on help from citizen scientists around the world, SOHO has become the single greatest comet finder of all time. This is all the more impressive since SOHO was not specifically designed to find comets, but to monitor the sun.

"Since it launched on December 2, 1995 to observe the sun, SOHO has more than doubled the number of comets for which orbits have been determined over the last three hundred years," says Joe Gurman, the U.S. project scientist for SOHO at NASA's Goddard Space Flight Center in Greenbelt, Md.

NASA's Next Mars Rover to Zap Rocks With Laser

2010-12-28T03:16:00.001-08:00

A rock-zapping laser instrument on NASA's next Mars rover has roots in a demonstration that Roger Wiens saw 13 years ago in a colleague's room at Los Alamos National Laboratory in New Mexico.

The Chemistry and Camera (ChemCam) instrument on the rover Curiosity can hit rocks with a laser powerful enough to excite a pinhead-size spot into a glowing, ionized gas. ChemCam then observes the flash through a telescope and analyzes the spectrum of light to identify the chemical elements in the target.

That information about rocks or patches of soil up to about 7 meters (23 feet) away will help the rover team survey the rover's surroundings and choose which targets to drill into, or scoop up, for additional analysis by other instruments on Curiosity. With the 10 science instruments on the rover, the team will assess whether any environments in the landing area have been favorable for microbial life and for preserving evidence about whether life existed. In late 2011, NASA will launch Curiosity and the other parts of the flight system, delivering the rover to the surface of Mars in August 2012.

Opportunity Studying a Football-Field Size Crater

2010-12-27T02:22:00.000-08:00

NASA's Mars Exploration Rover Opportunity reached a crater about the size of a football field—some 90 meters (295 feet) in diameter. The rover team plans to use cameras and spectrometers during the next several weeks to examine rocks exposed at the crater, informally named "Santa Maria."

A mosaic of image frames taken by Opportunity's navigation camera on Dec. 16 shows the crater's sharp rim and rocks ejected from the impact that had excavated the crater.

Opportunity completed its three-month prime mission on Mars in April 2004 and has been working in bonus extended missions since then. After the investigations at Santa Maria, the rover team plans to resume a long-term trek by Opportunity to the rim of Endeavour Crater, which is about 22 kilometers (14 miles) in diameter.

Cassini Finishes Sleigh Ride by Icy Moons

2010-12-22T00:46:00.001-08:00

On the heels of a successful close flyby of Saturn's moon Enceladus, NASA's Cassini spacecraft is returning images of Enceladus and the nearby moon Dione.

Several pictures show Enceladus backlit, with the dark outline of the moon crowned by glowing jets from the south polar region. The images show several separate jets, or sets of jets, emanating from the fissures known as "tiger stripes." Scientists will use the images to pinpoint the jet source locations on the surface and learn more about their shape and variability.

The Enceladus flyby took Cassini within about 48 kilometers (30 miles) of the moon's northern hemisphere. Cassini's fields and particles instruments worked on searching for particles that may form a tenuous atmosphere around Enceladus. They also hope to learn whether those particles may be similar to the faint oxygen- and carbon-dioxide atmosphere detected recently around Rhea, another Saturnian moon. The scientists were particularly interested in the Enceladus environment away from the jets emanating from the south polar region. Scientists also hope this flyby will help them understand the rate of micrometeoroid bombardment in the Saturn system and get at the age of Saturn's main rings.

Cassini Takes Close-Up of Enceladus Northern Hemisphere

2010-12-21T03:06:00.000-08:00

NASA's Cassini spacecraft will be making its close flyby of the northern hemisphere of Saturn's moon Enceladus today, Monday, Dec. 20. The closest approach will take place at 5:08 PM PST (8:08 EST) on Dec. 20, or 1:08 AM UTC on Dec. 21. The spacecraft will zip by at an altitude of about 48 kilometers (30 miles) above the icy moon's surface.

Cassini's fields and particles instruments will get priority during this flyby. They will be trying to characterize the particles that may form a tenuous atmosphere around Enceladus and see if they may be similar to the faint oxygen- and carbon-dioxide atmosphere detected recently around Rhea, another Saturnian moon. The instruments will be particularly interested in the Enceladus environment away from the jets emanating from the south polar region. A goal of the observations will be to try to measure the rate of dust coming off the moon from the bombardment of micrometeoroids alone. These measurements will help scientists understand the rate of micrometeoroid bombardment in the Saturn system, which will help them get at the age of Saturn's main rings.

NASA Spacecraft Provides Travel Tips for Mars Rover

2010-12-20T04:35:00.000-08:00

NASA's Mars Opportunity rover is getting important tips from an orbiting spacecraft as it explores areas that might hold clues about past Martian environments.

Researchers are using a mineral-mapping instrument aboard NASA's Mars Reconnaissance Orbiter to help the rover investigate a large ancient crater called Endeavour. The orbiter's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) is providing maps of minerals at Endeavour's rim that are helping the team choose which area to explore first and where to go from there. As Mars Reconnaissance Orbiter orbits more than 241 kilometers high (150 miles), the CRISM instrument provides mapping information for mineral exposures on the surface as small as a tennis court.

"This is the first time mineral detections from orbit are being used in tactical decisions about where to drive on Mars," said Ray Arvidson of Washington University in St. Louis. Arvidson is the deputy principal investigator for the Spirit and Opportunity rovers and a co-investigator for CRISM.

SORCE's Solar Spectral Surprise

2010-12-17T02:14:00.000-08:00

Two satellite instruments aboard NASA's Solar Radiation & Climate Experiment (SORCE) mission -- the Total Solar Irradiance Monitor (TIM) and the Solar Irradiance Monitor (SIM) -- have made daily measurements of the sun's brightness since 2003.

The two instruments are part of an ongoing effort to monitor variations in solar output that could affect Earth's climate. Both instruments measure aspects of the sun's irradiance, the intensity of the radiation striking the top of the atmosphere.

Instruments similar to TIM have made daily irradiance measurements of the entire solar spectrum for more than three decades, but the SIM instrument is the first to monitor the daily activity of certain parts of the spectrum, a measurement scientists call solar spectral irradiance.

NASA's Odyssey Spacecraft Sets Exploration Record on Mars

2010-12-16T03:19:00.000-08:00

NASA's Mars Odyssey, which launched in 2001, will break the record Wednesday for longest-serving spacecraft at the Red Planet. The probe begins its 3,340th day in Martian orbit at 5:55 p.m. PST (8:55 p.m. EST) on Wednesday to break the record set by NASA's Mars Global Surveyor, which orbited Mars from 1997 to 2006.

Odyssey's longevity enables continued science, including the monitoring of seasonal changes on Mars from year to year and the most detailed maps ever made of most of the planet. In 2002, the spacecraft detected hydrogen just below the surface throughout Mars' high-latitude regions. The deduction that the hydrogen is in frozen water prompted NASA's Phoenix Mars Lander mission, which confirmed the theory in 2008. Odyssey also carried the first experiment sent to Mars specifically to prepare for human missions, and found radiation levels around the planet from solar flares and cosmic rays are two to three times higher than around Earth.

Odyssey also has served as a communication relay, handling most of the data sent home by Phoenix and NASA's Mars Exploration Rovers Spirit and Opportunity. Odyssey became the middle link for continuous observation of Martian weather by NASA's Mars Global Surveyor and NASA's Mars Reconnaissance Orbiter.

Cassini Spots Potential Ice Volcano on Saturn Moon

2010-12-15T01:18:00.000-08:00

NASA's Cassini spacecraft has found possible ice volcanoes on Saturn's moon Titan that are similar in shape to those on Earth that spew molten rock.

Topography and surface composition data have enabled scientists to make the best case yet in the outer solar system for an Earth-like volcano landform that erupts in ice. The results were presented today at the American Geophysical Union meeting in San Francisco.

"When we look at our new 3-D map of Sotra Facula on Titan, we are struck by its resemblance to volcanoes like Mt. Etna in Italy, Laki in Iceland and even some small volcanic cones and flows near my hometown of Flagstaff," said Randolph Kirk, who led the 3-D mapping work, and is a Cassini radar team member and geophysicist at the U.S. Geological Survey (USGS) Astrogeology Science Center in Flagstaff, Ariz.

Global Eruption Rocks the Sun

2010-12-14T01:52:00.000-08:00

On August 1, 2010, an entire hemisphere of the sun erupted. Filaments of magnetism snapped and exploded, shock waves raced across the stellar surface, billion-ton clouds of hot gas billowed into space. Astronomers knew they had witnessed something big.

It was so big, it may have shattered old ideas about solar activity.

"The August 1st event really opened our eyes," says Karel Schrijver of Lockheed Martin’s Solar and Astrophysics Lab in Palo Alto, CA. "We see that solar storms can be global events, playing out on scales we scarcely imagined before."

Odyssey Orbiter Nears Martian Longevity Record

2010-12-09T23:37:00.000-08:00

By the middle of next week, NASA's Mars Odyssey orbiter will have worked longer at Mars than any other spacecraft in history.

Odyssey entered orbit around Mars on Oct. 24, 2001. On Dec. 15, the 3,340th day since that arrival, it will pass the Martian career longevity record set by its predecessor, Mars Global Surveyor, which operated in orbit from Sept. 11, 1997, to Nov. 2, 2006.

Odyssey made its most famous discovery -- evidence for copious water ice just below the dry surface of Mars -- during its first few months, and it finished its radiation-safety check for future astronauts before the end of its prime mission in 2004. The bonus years of extended missions since then have enabled many accomplishments that would not have been possible otherwise.

"The extra years have allowed us to build up the highest-resolution maps covering virtually the entire planet," said Odyssey Project Scientist Jeffrey Plaut of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

'Greener' Climate Prediction Shows Plants Slow Warming

2010-12-09T05:08:00.000-08:00

A new NASA computer modeling effort has found that additional growth of plants and trees in a world with doubled atmospheric carbon dioxide levels would create a new negative feedback – a cooling effect – in the Earth's climate system that could work to reduce future global warming.

The cooling effect would be -0.3 degrees Celsius (C) (-0.5 Fahrenheit (F)) globally and -0.6 degrees C (-1.1 F) over land, compared to simulations where the feedback was not included, said Lahouari Bounoua, of Goddard Space Flight Center, Greenbelt, Md. Bounoua is lead author on a paper detailing the results that will be published Dec. 7 in the journal Geophysical Research Letters.

Without the negative feedback included, the model found a warming of 1.94 degrees C globally when carbon dioxide was doubled.

NASA-Funded Research Discovers Life Built With Toxic Chemical

2010-12-08T01:35:00.001-08:00

NASA-funded astrobiology research has changed the fundamental knowledge about what comprises all known life on Earth.

Researchers conducting tests in the harsh environment of Mono Lake in California have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism substitutes arsenic for phosphorus in its cell components.

"The definition of life has just expanded," said Ed Weiler, NASA's associate administrator for the Science Mission Directorate at the agency's Headquarters in Washington. "As we pursue our efforts to seek signs of life in the solar system, we have to think more broadly, more diversely and consider life as we do not know it."

This finding of an alternative biochemistry makeup will alter biology textbooks and expand the scope of the search for life beyond Earth. The research is published in this week's edition of Science Express.

Sunspot 1112 Crackling with Solar Flares

2010-10-20T05:08:00.000-07:00

NASA - Fast-growing sunspot 1112 is crackling with solar flares. The three strongest of this 24 hour period: an M3-flare at 1910 UT on Oct. 16th, a C1-flare at 0900 UT and another C1-flare at 1740 UT on Oct. 17th. So far, none of the blasts has hurled a substantial CME toward Earth.

In addition, a vast filament of magnetism is cutting across the sun's southern hemisphere, measuring about 400,000 km. A bright 'hot spot' just north of the filament's midpoint is UV radiation from sunspot 1112. The proximity is no coincidence; the filament appears to be rooted in the sunspot below. If the sunspot flares, it could cause the entire structure to erupt. But so far, none of the flares has destabilized the filament.

Cassini takes Saturn Moons in Paintball Fight

2010-10-08T04:35:00.000-07:00

Scientists using data from NASA's Cassini spacecraft have learned that distinctive, colorful bands and splotches embellish the surfaces of Saturn's inner, mid-size moons. The reddish and bluish hues on the icy surfaces of Mimas, Enceladus, Tethys, Dione and Rhea appear to be the aftermath of bombardments large and small.

A paper based on the findings was recently published online in the journal Icarus. In it, scientists describe prominent global patterns that trace the trade routes for material exchange between the moons themselves, an outer ring of Saturn known as the E ring and the planet's magnetic environment. The finding may explain the mysterious Pac-Man thermal pattern on Mimas, found earlier this year by Cassini scientists, said lead author Paul Schenk, who was funded by a Cassini data analysis program grant and is based at the Lunar and Planetary Institute in Houston.

"The beauty of it all is how the satellites behave as a family, recording similar processes and events on their surfaces, each in its own unique way," Schenk said. "I don't think anyone expected that electrons would leave such obvious fingerprints on planetary surfaces, but we see it on several moons, including Mimas, which was once thought to be rather bland."

Schenk and colleagues processed raw images obtained by Cassini's imaging cameras from 2004 to 2009 to produce new, high-resolution global color maps of these five moons. The new maps used camera frames shot through visible-light, ultraviolet and infrared filters which were processed to enhance our views of these moons beyond what could be seen by the human eye.