Friday, November 27, 2009

NASA Assessing New Roles for Ailing QuikScat Satellite

Artist's concept of QuikScat
NASA mission managers are assessing options for future operations of the venerable QuikScat satellite following the age-related failure of a mechanism that spins the scatterometer antenna. This spinning antenna had been providing near-real-time ocean- surface wind speed and direction data over 90 percent of the global ocean every day.

In recent months, the QuikScat project team has been monitoring a pattern of increasing friction in the bearings that allow the antenna to spin, leading to increased resistance and strain on the motor that turns QuikScat's rotating antenna. This degradation was fully expected, as the spin mechanism was designed to last about 5 years.

After experiencing further difficulties over the weekend, the antenna stopped spinning early today, Nov. 23. The QuikScat spacecraft and scatterometer instrument themselves remain in otherwise good health. Should engineers be unable to restart the antenna, QuikScat will be unable to continue its primary science mission, as the antenna spin is necessary to estimate wind speed and direction and form the wide data swath necessary to obtain nearly global sampling.

Over the coming days, NASA managers will review contingency plans for restarting the antenna and assess options for using the mission in its present degraded state to advance Earth system science in the event the antenna cannot be restarted. For example, degraded scatterometer measurements from QuikScat can still be useful for cross-calibrating the mission's climate data record with measurements from other scatterometers, including the operational EUMETSAT ASCAT instrument, India's recently launched Oceansat-2 and a planned Chinese scatterometer. Specific operational forecasting applications such as polar ice measurements and limited hurricane observations may also be supportable.

By any measure of success, the 10-year-old QuikScat mission is a unique national resource that has achieved and far surpassed its science objectives. Designed for a two-year lifetime, QuikScat has been used around the globe by the world's operational meteorological agencies to improve weather forecasts and identify the location, size and strength of hurricanes and other storms in the open ocean. The mission has also provided critical information for monitoring, modeling, forecasting and researching our atmosphere, ocean and climate.

Wednesday, November 25, 2009

Cassini Captures Ghostly Dance of Saturn's Northern Lights

In the first video showing the auroras above the northern latitudes of Saturn, Cassini has spotted the tallest known "northern lights" in the solar system, flickering in shape and brightness high above the ringed planet.

The new video reveals changes in Saturn's aurora every few minutes, in high resolution, with three dimensions. The images show a previously unseen vertical profile to the auroras, which ripple in the video like tall curtains. These curtains reach more than 1,200 kilometers (750 miles) above the edge of the planet's northern hemisphere.

The new video and still images are online at: , and .

Auroras occur on Earth, Jupiter, Saturn and a few other planets, and the new images will help scientists better understand how they are generated.

"The auroras have put on a dazzling show, shape-shifting rapidly and exposing curtains that we suspected were there, but hadn't seen on Saturn before," said Andrew Ingersoll of the California Institute of Technology in Pasadena, who is a member of the Cassini imaging team that processed the new video. "Seeing these things on another planet helps us understand them a little better when we see them on Earth."
Cassini Captures Ghostly Dance of Saturn's Northern Lights A Cassini scientist explains the flickering "northern lights" high above Saturn, shown for the first time in a visible-light movie.Image credit: NASA/JPL/
Play now

Auroras appear mostly in the high latitudes near a planet's magnetic poles. When charged particles from the magnetosphere -- the magnetic bubble surrounding a planet -- plunge into the planet's upper atmosphere, they cause the atmosphere to glow. The curtain shapes show the paths that these charged particles take as they flow along the lines of the magnetic field between the magnetosphere and the uppermost part of the atmosphere.

Tuesday, November 24, 2009

Mystery of the Solar Tsunami—Solved

Violent events on the Sun can trigger waves much the same as earthquakes can trigger tsunamis on the Earth
Sometimes you really can believe your eyes. That's what NASA's Solar Terrestrial Relations Observatory (STEREO) is telling researchers about a controversial phenomenon on the sun known as the "solar tsunami."

Years ago, when solar physicists first witnessed a towering wave of hot plasma racing across the sun's surface, they doubted their senses. The scale of the wave was staggering: It rose up higher than Earth itself and rippled out from a central point in a circular pattern millions of kilometers in circumference. Skeptical observers suggested it might be a shadow of some kind—a trick of the satellite's eye—but surely not a real wave.

"Now we know," says Joe Gurman of the Solar Physics Laboratory at NASA's Goddard Space Flight Center. "Solar tsunamis are real."

The twin STEREO spacecraft confirmed their reality in February 2009 when sunspot 11012 unexpectedly erupted. The blast hurled a billion-ton cloud of gas (a coronal mass ejection, or CME) into space and sent a tsunami racing along the sun's surface. STEREO recorded the wave from two positions separated by 90 degrees, giving researchers an unprecedented view of the event.

"It was definitely a wave," says Spiros Patsourakos of George Mason University, lead author of a paper reporting the finding in Astrophysical Journal Letters. "Not a wave of water, but a giant wave of hot plasma and magnetism."

Friday, November 20, 2009

The View from the Center of Our Solar System

* NASA's Cassini spacecraft is helping to rewrite our understanding of the shape of our solar system as it moves through the local Milky Way galaxy.
* Previous models pictured our solar system as having a comet-like appearance. The new results suggest a picture more like a bubble.
* Cassini scientists created an image from this exotic region of space by detecting particles known as energetic neutral atoms.
* It complements data collected by NASA's Interstellar Boundary Explorer.

When NASA's Cassini spacecraft began orbiting Saturn five years ago, a dozen highly-tuned science instruments set to work surveying, sniffing, analyzing and scrutinizing the Saturnian system.

But Cassini recently revealed new data that appeared to overturn the decades-old belief that our solar system resembled a comet in shape as it moves through the interstellar medium (the matter between stars in our corner of the Milky Way galaxy).

Instead, the new results suggest our heliosphere more closely resembles a bubble - or a rat - being eaten by a boa constrictor: as the solar system passes through the "belly" of the snake, the ribs, which mimic the local interstellar magnetic field, expand and contract as the rat passes. An animation is available here

"At first I was incredulous," said Tom Krimigis, principal investigator of the Magnetospheric Imaging Instrument (MIMI) at Johns Hopkins University's Applied Physics Laboratory in Laurel, Md. "The first thing I thought was, 'What's wrong with our data?'"

Krimigis and his colleagues on the instrument team published the Cassini findings in the Nov. 13 issue of the journal Science, which featured complementary results from NASA's Interstellar Boundary Explorer (IBEX). Together, the results create the first map of the heliosphere and its thick outer layer known as the heliosheath, where solar wind streaming out from the sun gets heated and slowed as it interacts with the interstellar medium.

Wednesday, November 18, 2009

NASA's Wise Gets Ready to Survey the Whole Sky

NASA's Wide-field Infrared Survey Explorer, or Wise, is chilled out, sporting a sunshade and getting ready to roll. NASA's newest spacecraft is scheduled to roll to the pad on Friday, Nov. 20, its last stop before launching into space to survey the entire sky in infrared light.

Wise is scheduled to launch no earlier than 6:09 a.m. PST (9:09 a.m. EST) on Dec. 9 from Vandenberg Air Force Base in California. It will circle Earth over the poles, scanning the entire sky one-and-a-half times in nine months. The mission will uncover hidden cosmic objects, including the coolest stars, dark asteroids and the most luminous galaxies.

"The eyes of Wise are a vast improvement over those of past infrared surveys," said Edward "Ned" Wright, the principal investigator for the mission at UCLA. "We will find millions of objects that have never been seen before."

The mission will map the entire sky at four infrared wavelengths with sensitivity hundreds to hundreds of thousands of times greater than its predecessors, cataloging hundreds of millions of objects. The data will serve as navigation charts for other missions, pointing them to the most interesting targets. NASA's Hubble and Spitzer Space Telescopes, the European Space Agency's Herschel Space Observatory, and NASA's upcoming Sofia and James Webb Space Telescope will follow up on Wise finds.

"This is an exciting time for space telescopes," said Jon Morse, NASA's Astrophysics Division director at NASA Headquarters in Washington. "Many of the telescopes will work together, each contributing different pieces to some of the most intriguing puzzles in our universe."

Visible light is just one slice of the universe's electromagnetic rainbow. Infrared light, which humans can't see, has longer wavelengths and is good for seeing objects that are cold, dusty or far away. In our solar system, Wise is expected to find hundreds of thousands of cool asteroids, including hundreds that pass relatively close to Earth's path. Wise's infrared measurements will provide better estimates of asteroid sizes and compositions -- important information for understanding more about potentially hazardous impacts on Earth.

"With infrared, we can find the dark asteroids other surveys have missed and learn about the whole population. Are they mostly big, small, fluffy or hard?" said Peter Eisenhardt, the Wise project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

Saturday, November 14, 2009

New Moon Sets Stage for Brilliant Leonids Meteor Shower

A Leonids meteor explodes in Earth's upper atmosphere on Nov. 23, 1998.
This year's Leonids meteor shower peaks on Tuesday, Nov. 17. If forecasters are correct, the shower should produce a mild but pretty sprinkling of meteors over North America followed by a more intense outburst over Asia. The phase of the moon will be new -- setting the stage for what could be one of the best Leonid showers in years.

"We're predicting 20 to 30 meteors per hour over the Americas, and as many as 200 to 300 per hour over Asia," says Bill Cooke of the Meteoroid Environment Office at NASA's Marshall Space Flight Center. "Our forecast is in good accord with independent theoretical work by other astronomers."

Leonids are bits of debris from Comet Tempel-Tuttle. Every 33 years the comet visits the inner solar system and leaves a stream of dusty debris in its wake. Many of these streams have drifted across the November portion of Earth's orbit. Whenever our planet hits one, meteors appear to be flying out of the constellation Leo.

"We can predict when Earth will cross a debris stream with pretty good accuracy," says Cooke. "The intensity of the display is less certain, though, because we don't know how much debris is in each stream." Caveat observer!

Friday, November 13, 2009

Cyclone Phyan Raining on Tibet After Breaking a Record in India

Cyclone Phyan broke a 43 year record when it made landfall north of the city of Mumbai, India during the evening hours on November 11. NASA's Aqua satellite captured Phyan's landfall with one instrument, and a day later, another of Aqua's instruments show the storm's remnants raining Tibet as Phyan continues to dissipate.

Phyan is the first tropical cyclone to make an appearance in November in the Konkan region of India since 1996. The India Meteorological Department confirmed that the last November appearance of a storm in that region was 43 years ago. As Phyan was making landfall, NASA's Aqua satellite passed overhead, and the Moderate Imaging Spectroradiometer captured a stunning visual image of the storm on November 11 at 0845 UTC (3:45 ET).

November 12 at 1:30 p.m. local time (2:30 a.m. ET) another instrument on Aqua called the Atmospheric Infrared Sounder (AIRS) captured an image of Phyan's remnant cold clouds and showers over Tibet. The AIRS image showed that Phyan still had cold cloud tops as cold as -27F and was dumping moderate rainfall over Lake Manasarovar and Raksas Tal in Tibet.

The official final warning on Phyan was issued on November 11 at 1500 UTC (10 a.m. ET) from the U.S. Navy's Joint Typhoon Warning Center. Phyan's center was located near 19.2 degrees North latitude and 73.6 East longitude, about 30 miles east-northeast of Mumbai, India. Cyclone Phyan had maximum sustained winds near 40 knots (46 mph) and it was moving northeast near 16 mph.

According to, before Phyan came ashore, the storm caused the deaths of seven fishermen. As of this morning, November 12, there are still 100 fisherman missing in the Arabian Sea because of the rough conditions the cyclone created on its approach to its landfall. Pyhan also affected the Sugar cane industry. Sugar cane harvesting was delayed because of flooded fields in Maharashtra, India’s second-biggest producer. Maharashtra is a state located on India's western coast. Other reports cited damages to more than 7,500 homes. Almost 100 were destroyed from Phyan's tropical storm force winds as wind gusts to 55 mph were reported upon Phyan's landfall.

Wednesday, November 11, 2009

2012 – A Scientific Reality Check

Galileo spacecraft's view of Earth and MoonThere apparently is a great deal of interest in celestial bodies, and their locations and trajectories at the end of the calendar year 2012. Now, I for one love a good book or movie as much as the next guy. But the stuff flying around through cyberspace, TV and the movies is not based on science. There is even a fake NASA news release out there… So here is the scientific reality on the celestial happenings in the year 2012.

Nibiru, a purported large object headed toward Earth, simply put - does not exist. There is no credible evidence - telescopic or otherwise - for this object's existence. There is also no evidence of any kind for its gravitational affects upon bodies in our solar system.

I do however like the name Nibiru. If I ever get a pet goldflish (and I just may do that sometime in early 2013), Nibiru will be at the top of my list.

The Mayan calendar does not end in December 2012. Just as the calendar you have on your kitchen wall does not cease to exist after December 31, the Mayan calendar does not cease to exist on December 21, 2012. This date is the end of the Mayan long-count period, but then – just as your calendar begins again on January 1 - another long-count period begins for the Mayan calendar.

There are no credible predictions for worrisome astronomical events in 2012. The activity of the sun is cyclical with a period of roughly 11 years and the time of the next solar maximum is predicted to occur in the period 2010 – 2012. However, the Earth routinely experiences these periods of increased solar activity – for eons - without worrisome effects. The Earth’s magnetic field, which deflects charged particles from the sun, does reverse polarity on time scales of about 400,000 years but there is no evidence that a reversal, which takes thousands of years to occur, will begin in 2012. Even if this several thousand year-long magnetic field reversal were to begin, that would not affect the Earth’s rotation nor would it affect the direction of the Earth’s rotation axis… only Superman can do that.

The only important gravitational tugs experienced by the Earth are due to the moon and sun. There are no planetary alignments in the next few decades, Earth will not cross the galactic plane in 2012, and even if these alignments were to occur, their effects on the Earth would be negligible. Each December the Earth and Sun align with the approximate center of the Milky Way Galaxy but that is an annual event of no consequence.

The predictions of doomsday or dramatic changes on December 21, 2012 are all false. Incorrect doomsday predictions have taken place several times in each of the past several centuries. Readers should bear in mind what Carl Sagan noted several years ago; "extraordinary claims require extraordinary evidence."

For any claims of disaster or dramatic changes in 2012, the burden of proof is on the people making these claims. Where is the science? Where is the evidence? There is none, and all the passionate, persistent and profitable assertions, whether they are made in books, movies, documentaries or over the Internet, cannot change that simple fact. There is no credible evidence for any of the assertions made in support of unusual events taking place in December 2012.

Monday, November 09, 2009

2012: Beginning of the End or Why the World Won't End?

Remember the Y2K scare? It came and went without much of a whimper because of adequate planning and analysis of the situation. Impressive movie special effects aside, Dec. 21, 2012, won't be the end of the world as we know. It will, however, be another winter solstice.

Much like Y2K, 2012 has been analyzed and the science of the end of the Earth thoroughly studied. Contrary to some of the common beliefs out there, the science behind the end of the world quickly unravels when pinned down to the 2012 timeline. Below, NASA Scientists answer several questions that we're frequently asked regarding 2012.

Question (Q): Are there any threats to the Earth in 2012? Many Internet websites say the world will end in December 2012.
Answer (A): Nothing bad will happen to the Earth in 2012. Our planet has been getting along just fine for more than 4 billion years, and credible scientists worldwide know of no threat associated with 2012.

Q: What is the origin of the prediction that the world will end in 2012?
A: The story started with claims that Nibiru, a supposed planet discovered by the Sumerians, is headed toward Earth. This catastrophe was initially predicted for May 2003, but when nothing happened the doomsday date was moved forward to December 2012. Then these two fables were linked to the end of one of the cycles in the ancient Mayan calendar at the winter solstice in 2012 -- hence the predicted doomsday date of December 21, 2012.

Q: Does the Mayan calendar end in December 2012?
A: Just as the calendar you have on your kitchen wall does not cease to exist after December 31, the Mayan calendar does not cease to exist on December 21, 2012. This date is the end of the Mayan long-count period but then -- just as your calendar begins again on January 1 -- another long-count period begins for the Mayan calendar.

Q: Could a phenomena occur where planets align in a way that impacts Earth?
A: There are no planetary alignments in the next few decades, Earth will not cross the galactic plane in 2012, and even if these alignments were to occur, their effects on the Earth would be negligible. Each December the Earth and sun align with the approximate center of the Milky Way Galaxy but that is an annual event of no consequence.

Thursday, November 05, 2009

Exoplanet House of Horrors

Astronomers may be closer than ever to discovering a planet that’s habitable like our own, but along the way they’ve discovered some very scary exoplanets – places where conditions are far too harsh for life as we know it to exist.

We’ve rounded up some of the most frightening, deadly exoplanets, places that make even the scariest haunted house on Earth pale in comparison.

Radiation Bath, Anyone?

The pulsar planets PSR B1257+12 b, c, and d are all that remains of a dead solar system. They are constantly beamed with intense radiation.The exoplanets PSR B1257+12 b, c and d were among the first discovered, and also happen to be three of the weirdest. The entire system is a graveyard, remnants of what used to be a normal, functional solar system before the star blew apart in a giant explosion known as a supernova.

The massive shockwave from the supernova stripped away any atmosphere or living creatures that might have once lived on these planets, leaving behind ghostly, rocky shells, dead planets orbiting the corpse of an extinct star.

Except that PSR B1257+12 isn’t all dead - the remaining core from the old star has become a zombie star called a pulsar. Literally spinning in its grave, PSR B1257+12 makes a full rotation every 6.22 milliseconds and emits an intense beam of radiation that can be detected from Earth. The star’s unfortunate planets are thus bathed in deadly radiation on a regular basis, making sure that this system remains a cosmic no-man’s land.

A Mighty Wind

HD 189733 b may have winds that blow up to 22,000 mphThe sound of howling wind is a must for any Earth-based haunted house, but weather conditions on HD 189733 b make it a very dangerous place to go trick-or-treating.

At first glance, HD 189733 b looks like the typical “hot Jupiter” – a huge gas planet perched dangerously close to a burning-hot star, with daytime temperatures around a balmy 1,770 degrees Fahrenheit. HD 189733 b is “tidally locked” in its orbit, meaning that the same side of the planet always faces its star.

But when scientists measured the planet’s nighttime temperature, they were shocked to find that it was only 500 degrees cooler. How does the back side of the planet stay so warm?

The answer is wind: insanely fast, dangerous wind that whisks heat from day-side to night-side at a speed of 4,500 mph, nearly six times the speed of sound. In fact, astronomers estimate that wind speeds might top out at 22,000 mph, conditions that make hurricanes on Earth look like a breezy day at the beach.

Needless to say, kite-flying on HD 189733 b is not recommended – unless you’re flying one from the cockpit of a fighter jet.

Boil, Boil, Toil and Trouble

HD 209458’s boiling atmosphere is being ripped from the planet as it orbits its starThe planet HD 209458 b has a few things in common with Earth: water vapor, methane, and carbon dioxide in its atmosphere, key ingredients for life on our planet. Don’t be fooled, though, because this planet is a roiling cauldron of almost unimaginable heat.

Even the hottest summer days on Earth don’t get as dangerous as the conditions on HD 209458 b, a planet that orbits so close to its host star that its atmosphere is literally boiling off, ripped away from the planet as it whips around on its breakneck 3.5-day orbit. The gas that escapes from HD 209458 b forms a tail about 124,000 miles (200,000 km) long.

Scientists have found many planets like HD 209458 b – huge gas giants that orbit hazardously close to their stars and have hellishly hot, poisonous atmospheres. Sometimes, planets like these can be in danger of being swallowed whole by their host stars, as may be the case for the doomed world WASP-18b.

As far as planets go, WASP-18b is on death’s doorstep. There’s a good chance that it will be torn apart completely within the next million years, when it finally spirals too close to its star. Scientists will know within 10 years whether or not WASP-18b is on a funeral march towards its untimely demise.

All Alone and Very, Very Cold

With an estimated temperature of just 50K, OGLE-2005-BLG-390L b is the chilliest exoplanet yet discovered.While most of the exoplanets found so far are hellishly hot, OGLE-2005-BLG-390L b has the distinction of being the coldest exoplanet yet discovered.

The planet takes about 10 Earth years to orbit its tiny dwarf star, and it’s a chilly trip; the average temperature on OGLE-2005-BLG-390L b is 50 Kelvin, or minus 370 degrees Fahrenheit. A good costume for trick-or-treating on this frigid planet would be a toasty self-heating spacesuit, an oxygen supply, ice skates and plenty of hot cocoa.

Of course, don’t expect to find many houses with candy here, because despite the fact that it’s just a few times bigger than Earth, OGLE-2005-BLG-390L b is an uninhabitable ice ball stuck in a perpetual winter freeze. Even the coldest Halloween night in Antarctica is a balmy paradise compared to this frosty world.

Wednesday, November 04, 2009

NASA's Mars Odyssey Alters Orbit to Study Warmer Ground

NASA's long-lived Mars Odyssey spacecraft has completed an eight-month adjustment of its orbit, positioning itself to look down at the day side of the planet in mid-afternoon instead of late afternoon.

This change gains sensitivity for infrared mapping of Martian minerals by the orbiter's Thermal Emission Imaging System camera. Orbit design for Odyssey's first seven years of observing Mars used a compromise between what worked best for the infrared mapping and for another onboard instrument.

"The orbiter is now overhead at about 3:45 in the afternoon instead of 5 p.m., so the ground is warmer and there is more thermal energy for the camera's infrared sensors to detect," said Jeffrey Plaut of NASA's Jet Propulsion Laboratory, Pasadena, Calif., project scientist for Mars Odyssey.

Some important mineral discoveries by Odyssey stem from mapping done during six months early in the mission when the orbit geometry provided mid-afternoon overpasses. One key example: finding salt deposits apparently left behind when large bodies of water evaporated.

"The new orbit means we can now get the type of high-quality data for the rest of Mars that we got for 10 or 20 percent of the planet during those early six months," said Philip Christensen of Arizona State University, Tempe, principal investigator for the Thermal Emission Imaging System.

Tuesday, November 03, 2009

The Sun's Sneaky Variability

Every 11 years, the sun undergoes a furious upheaval. Dark sunspots burst forth from beneath the sun's surface. Explosions as powerful as a billion atomic bombs spark intense flares of high-energy radiation. Clouds of gas big enough to swallow planets break away from the sun and billow into space. It's a flamboyant display of stellar power.

Almost none of the drama of Solar Maximum is visible to the human eye. Look at the sun in the noontime sky and—ho-hum—it's the same old bland ball of bright light.

"The problem is, human eyes are tuned to the wrong wavelength," explains Tom Woods, a solar physicist at the University of Colorado in Boulder. "If you want to get a good look at solar activity, you need to look in the EUV."