New Earth-like planet may have water, life

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.

Diamond stud

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Solar System May Have Lost Fifth Giant Planet

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.

Diamond stud

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Our solar system might have once had an extra gas planet

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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Solar system with Earth-size planet found

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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New Animation Depicts Next Mars Rover in Action

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.

Comet Elenin: Preview of a Coming Attraction

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."

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Beams of Electrons Link Saturn With Its Moon Enceladus

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.

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Next Mars Rover Gets a Test Taste of Mars Conditions

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.

Spectacular First Images from the Rejuvenated Hubble Space Telescope

Astronomers have declared NASA's Hubble Space Telescope a fully rejuvenated observatory with the release of observations from four of its six operating science instruments. Sen. Barbara Mikulski of Maryland unveiled the images at NASA Headquarters in Washington, DC.

"This marks a new beginning for Hubble," said Ed Weiler, associate administrator for NASA's Science Mission Directorate. "The telescope was given an extreme makeover and now is significantly more powerful than ever, well-equipped to last into the next decade."

Topping the list of new views are colorful, multi-wavelength pictures of far-flung galaxies, a densely packed star cluster, an eerie "pillar of creation," and a "butterfly" nebula. Hubble's suite of new instruments allows it to study the universe across a wide swath of the light spectrum, from ultraviolet all the way to near-infrared. In addition, scientists released spectroscopic observations that slice across billions of light-years to probe the cosmic-web structure of the universe and map the distribution of elements that are fundamental to life as we know it.