Thursday, September 30, 2010

NASA Solar System Exhibition Arrives at Dulles Airport

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NASA and the Metropolitan Washington Airports Authority unveiled a photography exhibition at Dulles International Airport in Chantilly, Va., where ticketed airline travelers can view space science discoveries and relish the beauty and majesty of our solar system.

“NASA presents BEYOND: Visions of Our Solar System,” will be shown at Dulles’ Gateway Gallery -- a pedestrian passageway located between the new AeroTrain C-gates station and Concourse C. Approximately 10,000 to 13,000 passengers transit the area daily. The exhibit, on display until March 31, 2011, features 46 backlit photographic images displayed in light boxes.

“This vista will not only allow NASA to share its science activities with the public in a unique venue, but it will also allow them to see our future possible travel destinations,” said James Green, director of the Planetary Science Division in the Science Mission Directorate at NASA Headquarters in Washington.

The images displayed include one of Jupiter’s Great Red Spot, which is a vast cyclonic storm system about two times the size of Earth, surrounded by other oval storms and banded clouds. Another shows Uranus with very faint rings, which may be made of countless fragments of water ice. There also are recent images from NASA’s Hubble Space Telescope and Cassini spacecraft.

An exhibit of similar images is currently on display at the National Air and Space Museum in Washington. The images were rendered by photographic artist Michael Benson.

For more information visit http://www.nasa.gov/topics/solarsystem/features/dulles_exhibit.html

Wednesday, September 29, 2010

Atmosphere Checked, One Mars Year Before a Landing

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What will the Martian atmosphere be like when the next Mars rover descends through it for landing in August of 2012?

An instrument studying the Martian atmosphere from orbit has begun a four-week campaign to characterize daily atmosphere changes, one Mars year before the arrival of the Mars Science Laboratory rover, Curiosity. A Mars year equals 687 Earth days.

The planet's thin atmosphere of carbon dioxide is highly repeatable from year to year at the same time of day and seasonal date during northern spring and summer on Mars.

The Mars Climate Sounder instrument on NASA's Mars Reconnaissance Orbiter maps the distribution of temperature, dust, and water ice in the atmosphere. Temperature variations with height indicate how fast air density changes and thus the rates at which the incoming spacecraft slows down and heats up during its descent.

"It is currently one Mars year before the Mars Science Laboratory arrival season," said atmospheric scientist David Kass of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "This campaign will provide a set of observations to support the Mars Science Laboratory engineering team and Mars atmospheric modelers. The information will constrain the expected climate at their landing season. It will also help define the range of possible weather conditions on landing day."

During the four years the Mars Climate Sounder has been studying the Martian atmosphere, its observations have seen conditions only at about three in the afternoon and three in the morning. For the new campaign, the instrument team is inaugurating a new observation mode, looking to both sides as well as forward. This provides views of the atmosphere earlier and later in the day by more than an hour, covering the range of possible times of day that the rover will pass through the atmosphere before landing.

JPL, a division of the California Institute of Technology, provided the Mars Climate Sounder instrument and manages the Mars Reconnaissance Orbiter and Mars Science Laboratory projects for NASA's Science Mission Directorate, Washington.

For more information visit http://www.nasa.gov/mission_pages/MRO/news/mro20100929.html

Tuesday, September 28, 2010

Light Show Over the VAB

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Lightning lights up the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida during thunderstorms on Monday, Sept. 27, 2010. The Vehicle Assembly Building, or VAB, is one of the largest buildings in the world. Originally built for assembly of Apollo and Saturn vehicles, it was later modified to support space shuttle operations. High Bays 1 and 3 are used for integration and stacking of the complete Space Shuttle vehicle. High Bay 2 is used for external tank (ET) checkout and storage and as a contingency storage area for orbiters. High Bay 4 is also used for ET checkout and storage, as well as for payload canister operations and solid rocket boster contingency handling.

For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1769.html

Sunday, September 26, 2010

Solar Storms can Change Directions, Surprising Forecasters

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Solar storms don't always travel in a straight line. But once they start heading in our direction, they can accelerate rapidly, gathering steam for a harder hit on Earth's magnetic field.

So say researchers who have been using data from NASA's twin STEREO spacecraft to unravel the 3D structure of solar storms. Their findings are presented in today's issue of Nature Communications.

"This really surprised us," says co-author Peter Gallagher of Trinity College in Dublin, Ireland. "Solar coronal mass ejections (CMEs) can start out going one way—and then turn in a different direction."

The result was so strange, at first they thought they'd done something wrong. After double- and triple-checking their work on dozens of eruptions, however, the team knew they were onto something.

"Our 3D visualizations clearly show that solar storms can be deflected from high solar latitudes and end up hitting planets they might otherwise have missed," says lead author Jason Byrne, a graduate student at the Trinity Center for High Performance Computing.

The key to their analysis was an innovative computing technique called "multiscale image processing." Gallagher explains:

"'Multiscale processing' means taking an image and sorting the things in it according to size. Suppose you're interested in race cars. If you have a photo that contains a bowl of fruit, a person, and a dragster, you could use multiscale processing to single out the race car and study its characteristics."

In medical research, multiscale processing has been used to identify individual nuclei in crowded pictures of cells. In astronomy, it comes in handy for picking galaxies out of a busy star field. Gallagher and colleagues are the first to refine and use it in the realm of solar physics.

"We applied the multiscale technique to coronagraph data from NASA's twin STEREO spacecraft," Gallagher continues. "Our computer was able to look at starry images cluttered with streamers and bright knots of solar wind and zero in on the CMEs."

STEREO-A and STEREO–B are widely separated and can see CMEs from different points of view. This allowed the team to create fully-stereoscopic models of the storm clouds and track them as they billowed away from the sun.

One of the first things they noticed was how CMEs trying to go "up"—out of the plane of the solar system and away from the planets—are turned back down again. Gallagher confesses that they had to "crack the books" and spend some time at the white board to fully understand the phenomenon. In the end, the explanation was simple:

The sun's global magnetic field, which is shaped like a bar magnet, guides the wayward CMEs back toward the sun's equator. When the clouds reach low latitudes, they get caught up in the solar wind and head out toward the planets—"like a cork bobbing along a river," says Gallagher.

Once a CME is embedded in the solar wind, it can experience significant acceleration. "This is a result of aerodynamic drag," says Byrne. "If the wind is blowing fast enough, it drags the CME along with it—something we actually observed in the STEREO data."

Past studies from other missions had revealed tantalizing hints of this CME-redirection and acceleration process, but STEREO is the first to see it unfold from nearly beginning to end.

"The ability to reconstruct the path of a solar storm through space could be of great benefit to forecasters of space weather at Earth," notes Alex Young, STEREO Senior Scientist at the Goddard Space Flight Center. "Knowing when a CME will arrive is crucial for predicting the onset of geomagnetic storms."

"Furthermore," he says, "the image processing techniques developed by the Trinity team in collaboration with NASA Goddard can be used in applications ranging from surveillance to medical diagnostics."

For more information visit http://science.nasa.gov/science-news/science-at-nasa/2010/21sep_zigzag/

Thursday, September 23, 2010

Dust Models Paint Alien's View of Solar System

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New supercomputer simulations tracking the interactions of thousands of dust grains show what the solar system might look like to alien astronomers searching for planets. The models also provide a glimpse of how this view might have changed as our planetary system matured.

"The planets may be too dim to detect directly, but aliens studying the solar system could easily determine the presence of Neptune -- its gravity carves a little gap in the dust," said Marc Kuchner, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Md. who led the study. "We're hoping our models will help us spot Neptune-sized worlds around other stars."

The dust originates in the Kuiper Belt, a cold-storage zone beyond Neptune where millions of icy bodies -- including Pluto -- orbit the sun. Scientists believe the region is an older, leaner version of the debris disks they've seen around stars like Vega and Fomalhaut.

"Our new simulations also allow us to see how dust from the Kuiper Belt might have looked when the solar system was much younger," said Christopher Stark, who worked with Kuchner at NASA Goddard and is now at the Carnegie Institution for Science in Washington, D.C. "In effect, we can go back in time and see how the distant view of the solar system may have changed."

Kuiper Belt objects occasionally crash into each other, and this relentless bump-and-grind produces a flurry of icy grains. But tracking how this dust travels through the solar system isn't easy because small particles are subject to a variety of forces in addition to the gravitational pull of the sun and planets.

The grains are affected by the solar wind, which works to bring dust closer to the sun, and sunlight, which can either pull dust inward or push it outward. Exactly what happens depends on the size of the grain.

The particles also run into each other, and these collisions can destroy the fragile grains. A paper on the new models, which are the first to include collisions among grains, appeared in the Sept. 7 edition of The Astronomical Journal.

"People felt that the collision calculation couldn't be done because there are just too many of these tiny grains too keep track of," Kuchner said. "We found a way to do it, and that has opened up a whole new landscape."

With the help of NASA's Discover supercomputer, the researchers kept tabs on 75,000 dust particles as they interacted with the outer planets, sunlight, the solar wind -- and each other.

The size of the model dust ranged from about the width of a needle's eye (0.05 inch or 1.2 millimeters) to more than a thousand times smaller, similar in size to the particles in smoke. During the simulation, the grains were placed into one of three types of orbits found in today's Kuiper Belt at a rate based on current ideas of how quickly dust is produced.


From the resulting data, the researchers created synthetic images representing infrared views of the solar system seen from afar.

Through gravitational effects called resonances, Neptune wrangles nearby particles into preferred orbits. This is what creates the clear zone near the planet as well as dust enhancements that precede and follow it around the sun.

"One thing we've learned is that, even in the present-day solar system, collisions play an important role in the Kuiper Belt's structure," Stark explained. That's because collisions tend to destroy large particles before they can drift too far from where they're made. This results in a relatively dense dust ring that straddles Neptune's orbit.

To get a sense of what younger, heftier versions of the Kuiper Belt might have looked like, the team sped up the dust production rate. In the past, the Kuiper Belt contained many more objects that crashed together more frequently, generating dust at a faster pace. With more dust particles came more frequent grain collisions.

Using separate models that employed progressively higher collision rates, the team produced images roughly corresponding to dust generation that was 10, 100 and 1,000 times more intense than in the original model. The scientists estimate the increased dust reflects conditions when the Kuiper Belt was, respectively, 700 million, 100 million and 15 million years old.

"We were just astounded by what we saw," Kuchner said.

As collisions become increasingly important, the likelihood that large dust grains will survive to drift out of the Kuiper Belt drops sharply. Stepping back through time, today's broad dusty disk collapses into a dense, bright ring that bears more than a passing resemblance to rings seen around other stars, especially Fomalhaut.

"The amazing thing is that we've already seen these narrow rings around other stars," Stark said. "One of our next steps will be to simulate the debris disks around Fomalhaut and other stars to see what the dust distribution tells us about the presence of planets."

The researchers also plan to develop a more complete picture of the solar system's dusty disk by modeling additional sources closer to the sun, including the main asteroid belt and the thousands of so-called Trojan asteroids corralled by Jupiter's gravity.

For more information visit http://www.nasa.gov/topics/solarsystem/features/dust-model.html

Wednesday, September 22, 2010

NASA's CloudSat Satellite and GRIP Aircraft Profile Hurricane Karl

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NASA's CloudSat satellite captured a profile of Hurricane Karl as it began making landfall in Mexico today. The satellite data revealed very high, icy cloud tops in Karl's powerful thunderstorms, and moderate to heavy rainfall from the storm.

Meanwhile, NASA's "GRIP" mission was also underway as aircraft were gathering valuable data about Hurricane Karl as he moves inland. NASA's Genesis and Rapid Intensification Processes mission (known as GRIP) is still underway and is studying the rapid intensification of storms, and that's exactly what Karl did on Thursday Sept. 16 overnight into Friday, Sept. 17. During that time, Karl went from a tropical storm to a Category 3 hurricane, and NASA's GRIP aircraft flew into Karl a number of times collecting valuable data on its rapid intensification.

In fact, three of NASA's science aircraft completed successful coordinated flights over Hurricane Karl on Thursday, Sept. 16, in the southern Gulf of Mexico. The DC-8 conducted 6 passes over the center of circulation with a butterfly pattern about the eye on the final pass. The Global Hawk flew 6 coordinated legs with the DC-8 over the storm for a total of 20 passes over the eye of the hurricane. The Global Hawk returned to its base of operations in southern California early Friday morning, Sept. 17.

NASA’s DC-8, based in Florida, and WB-57, based in Texas, went back to Hurricane Karl as it approached the coast of Mexico on the afternoon of Friday, Sept. 17. The two research aircraft also observed the hurricane on Sept. 16 along with NASA’s Global Hawk. For more information on the NASA GRIP mission, visit: www.nasa.gov/grip.

From its vantage point in space, NASA's CloudSat satellite has the unique capability of seeing a tropical storm from its side. CloudSat's Cloud Profiling Radar captured a sideways look across Hurricane Karl's clouds at 07:59 UTC (3:59 a.m. EDT) Sept. 17.

CloudSat's 55 second scan showed cloud tops were over 8 miles high, and indicated ice in them. In fact, the highest clouds in Karl at the time of the image were as cold as -40 Celsius (-40 Fahrenheit) to -60C (-76 Fahrenheit). CloudSat also showed strong rainfall exceeding 30mm/hr (1.18 inches/hour) which confirms the moderate to heavy rain that was falling from the storm.

Hurricane warnings and watches are still in effect as Karl slowly makes landfall and moves inland. A hurricane warning is in effect for the coast of Mexico from Veracruz to Cabo Rojo. A hurricane watch is in effect for the coast of Mexico north of Cabo Rojo To La Cruz. A tropical storm warning is in effect for the coast of Mexico north of Cabo Rojo to La Cruz and south of Veracruz to Punta El Lagarto.

Hurricane Karl built up a lot of power overnight. On Sept. 16 at 5 p.m. EDT, his maximum sustained winds were near 80 mph. On Sept. 17 at 11 a.m. EDT, Karl's maximum sustained winds were near 120 mph with higher gusts. Karl is a Category 3 on the Saffir-Simpson hurricane scale. Hurricane force winds extend 25 miles out from Karl's center and tropical storm force winds extend out to 90 miles, making Karl about 180 miles in diameter. For size comparison, Hurricane Igor is 550 miles across out in the Atlantic Ocean.

NASA's Terra satellite flew over Karl on Sept. 16 at 17:20 UTC (1:20 p.m. EDT) and captured a visible image of Karl's cloud cover and extent. The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument captured a visible image of Karl. At that time Karl was already a hurricane, but did not have a visible eye.

Karl is making landfall this afternoon (Sept. 17) and is moving west near 8 mph. Karl will move inland tonight and Saturday. Karl's minimum central pressure is 967 millibars.

Karl is bringing a lot of bad weather to Mexico this weekend. The National Hurricane Center said "A dangerous storm surge will raise water levels by as much as 12 to 15 feet above normal tide levels along the immediate coast near and to the north of where the center makes landfall. Near the coast...the surge will be accompanied by large and destructive waves." Hurricane-force winds will continue to spread inland, and rainfall accumulations will range from 5 to 10 inches across the central and southern Mexican gulf coast region, with isolated amounts as high as 15 inches.

For more information visit http://www.nasa.gov/mission_pages/hurricanes/missions/grip/main/GRIP_status_09_17_10.html

Tuesday, September 21, 2010

Laser Tool for Studying Mars Rocks Delivered to JPL

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The NASA Mars Science Laboratory Project's rover, Curiosity, will carry a newly delivered laser instrument named ChemCam to reveal what elements are present in rocks and soils on Mars up to 7 meters (23 feet) away from the rover.

The laser zaps a pinhead-sized area on the target, vaporizing it. A spectral analyzer then examines the flash of light produced to identify what elements are present.

The completed and tested instrument has been shipped to JPL from Los Alamos for installation onto the Curiosity rover at JPL.

ChemCam was conceived, designed and built by a U.S.-French team led by Los Alamos National Laboratory, Los Alamos, N.M.; NASA's Jet Propulsion Laboratory, Pasadena, Calif.; the Centre National d'Études Spatiales (the French national space agency); and the Centre d'Étude Spatiale des Rayonnements at the Observatoire Midi-Pyrénées, Toulouse, France.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-310

Monday, September 20, 2010

NASA Satellites and Aircraft Studied Hurricane Karl Before it Faded

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This visible image from the MODIS instrument on NASA's Aqua satellite shows Hurricane Karl after landfall on Sept. 17 at 19:35 UTC (3:35 p.m. EDT). About 2/3rds of Karl was already over land by that time.

Hurricane Karl made landfall near Veracruz, Mexico on Friday, Sept. 17 and moved inland over Mexico's rugged terrain, which took the punch out of the storm. As Karl was moving into Mexico, NASA aircraft and NASA satellites were gathering data from this storm that jumped from a tropical storm to a Category 3 hurricane the day before.

Karl had maximum sustained winds of 115 mph when it made landfall on Friday afternoon, Sept. 17. That made Karl a Category three hurricane on the Saffir-Simpson scale, and a major hurricane to boot.

On that day, NASA's Genesis and Rapid Intensification Processes (GRIP) aircraft were flying over Karl and taking readings of the storm's winds, temperature, pressure and more. The DC-8 aircraft was one of the planes that flew into Karl at an altitude of 37,000 feet on the afternoon of Friday, Sept. 17, about 3 hours after Hurricane Karl made landfall in Mexico. The DC-8 aircraft took off from its base in Fort Lauderdale, Fla. All nine instruments installed on the DC-8 collected data during its flight over the storm system, and dropsondes were launched successfully to aid the other instruments in gauging wind profiles and moisture content.

Meanwhile, NASA's WB-57 took off from its base in Houston, Texas and joined the DC-8 for flights over Hurricane Karl in mid-afternoon on Sept. 17. The WB-57 flew higher than the DC-8 aircraft, at an altitude between 56,000 and 58.000 feet. The WB-57 has two instruments aboard to study tropical cyclones: the Advanced Microwave Precipitation Radiometer (AMPR) and the HIRAD (Hurricane Imaging Radiometer). AMPR studies rain cloud systems, but are also useful to studies of various ocean and land surface processes. The HIRAD measures strong ocean surface winds through heavy rain, providing information on both rain rate and wind speed. For more information on the NASA GRIP Mission, visit: www.nasa.gov/grip.

This photo was taken looking out of the window of the DC-8 aircraft on the afternoon of Friday, Sept. 17, about 3 hours after Hurricane Karl made landfall in Mexico. It was taken from an altitude of about 37,000 feet while flying over Karl.
From its vantage point in space, NASA's Aqua satellite captured a much wider view of Hurricane Karl after it made landfall on Sept. 17. The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on Aqua captured a visible image at 19:35 UTC (3:35 p.m. EDT) and showed that two-thirds of Karl was already over land.

Karl's heavy rainfall was responsible for inland flooding and evacuations. Reports indicated that almost half a million people were without electricity, and over 20,000 homes were damaged or flooded. Over 40,000 people were evacuated from the municipalities of Jamapa, La Antigua, Medellin de Bravo, Cotaxtla and Actopanm. Reports indicated eight people missing and seven dead from Karl's rampage.

By Saturday morning, Sept. 18, Karl's maximum sustained winds were down to 25 mph. By Sunday, Sept. 19, the National Hurricane Center in Miami, Fla. proclaimed that Karl had dissipated over inland Mexico.

For more information visit http://www.nasa.gov/mission_pages/hurricanes/missions/grip/news/NASAStudiedKarl.html

Sunday, September 19, 2010

NASA Hosts Symposium About Latin American Space Partnerships

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NASA hosted government representatives from several Latin American countries in Washington on Thursday to share information about the agency's work in that region and discuss potential future partnerships.

The event highlighted potential opportunities for cooperation with NASA in Earth science, space and International Space Station research, applications and education initiatives.

The participants discussed some of NASA's ongoing work in Latin America, including the NASA and U.S. Agency for International Development’s (USAID) Regional Visualization and Monitoring System. The satellite system provides information from Earth observations to help local decision makers respond to natural disasters, and environmental threats, such as air pollution and fires.

"Our future in space is of global interest," said Michael O'Brien, NASA's associate administrator for International and Interagency Relations. "NASA has a long history of cooperation in Latin America, and our agency stands ready to continue that cooperation with interested partners in the region. This symposium was an excellent opportunity to continue our dialogue on areas of mutual interest with an eye toward future cooperation."

Symposium attendees also discussed how to access data from NASA's many space-based resources and how to pursue new partnerships with agency-sponsored researchers. NASA has more than 30 agreements with 20 Latin American countries covering Earth and space science, research on the space station, new uses for groundbreaking technology and education.

For more information visit http://www.nasa.gov/home/hqnews/2010/sep/10-224_Latin_American_Symposium.html

Friday, September 17, 2010

Hurricane Igor, Unchained, in NASA Satellite Images

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While its intensity has dropped slightly, massive Hurricane Igor remains a powerful Category Three storm, with maximum sustained wind speeds of 105 knots (115 miles per hour) as it continues on a projected collision course with Bermuda this weekend. The storm is bringing large swells to the Lesser Antilles, Virgin Islands, Puerto Rico, Hispaniola, the Bahamas and the east coast of the United States.

Igor is one of three hurricanes currently active in the Atlantic/Caribbean Sea/Gulf of Mexico - only the ninth time in recorded history that three hurricanes were active in this region at the same time. The other current storms are Julia in the central Atlantic, a Category One storm with maximum sustained winds of 75 knots (85 miles per hour), and Karl, which made landfall today in southeastern Mexico and is currently a Category One storm with maximum sustained winds of 95 knots (110 miles per hour).

All three storms were captured in infrared in these Sept. 17, 2010 images by the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite, built and managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif. The AIRS data create accurate 3-D maps of atmospheric temperature, water vapor and clouds, data that are useful to hurricane forecasters. The images show the temperature of the storms' cloud tops or the surface of Earth in cloud-free regions. The coldest cloud-top temperatures appear in purple, indicating towering cold clouds and heavy precipitation. The infrared signal of AIRS does not penetrate through clouds. Where there are no clouds, AIRS reads the infrared signal from the surface of the ocean waters, revealing warmer temperatures in orange and red.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-305

Thursday, September 16, 2010

NASA’s Armada of Research Aircraft Monitor Hurricane Karl

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NASA’s armada of research aircraft arrived at Hurricane Karl on Thursday, Sept. 16.

The Global Hawk left southern California at 6 a.m. PDT for a 24-hour roundtrip flight to observe the storm. The DC-8, temporarily based in Ft Lauderdale, Fla., took off at approximately 1 p.m. EDT for about seven hours of research time. The WB-57, based in Houston, Texas, began its six-hour mission at about 12:30 CDT. The aircraft rendezvoused at the storm, which is currently in the Bay of Campeche in the Gulf of Mexico.

The Global Hawk’s altitude is about 60,000 feet over Karl, while the WB-57 is flying between 56,000 and 58.000 feet. The DC-8 joins the other two at an altitude of between 33,000 and 37,000 feet.

Today’s coordinated flights are the first time during the GRIP campaign that NASA’s three aircraft have been in the same storm at the same time. In addition, aircraft from the National Oceanic and Atmospheric Administration, the National Science Foundation and the Air Force are monitoring Hurricane Karl.

The Genesis and Rapid Intensification Processes, or GRIP, mission is a six-week study of the formation and strengthening of tropical storms in the Gulf of Mexico and western Atlantic Ocean.

For more information visit http://www.nasa.gov/mission_pages/hurricanes/missions/grip/main/GRIP_status_09_16_10.html

Wednesday, September 15, 2010

The Rosette Nebula

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Located about 5,000 light years from Earth, this composite image shows the Rosette star formation region. Data from the Chandra X-ray Observatory are colored red and outlined by a white line. The X-rays reveal hundreds of young stars in the central cluster and fainter clusters on either side. Optical data from the Digitized Sky Survey and the Kitt Peak National Observatory (purple, orange, green and blue) show large areas of gas and dust, including giant pillars that remain behind after intense radiation from massive stars has eroded the more diffuse gas.

A recent Chandra study of the cluster on the right side of the image, named NGC 2237, provides the first probe of the low-mass stars in this satellite cluster. Previously only 36 young stars had been discovered in NGC 2237, but the Chandra work has increased this sample to about 160 stars. The presence of several X-ray emitting stars around the pillars and the detection of an outflow -- commonly associated with very young stars -- originating from a dark area of the optical image indicates that star formation is continuing in NGC 2237. By combining these results with earlier studies, scientists conclude that the central cluster formed first, followed by expansion of the nebula, which triggered the formation of the two neighboring clusters, including NGC 2237.

For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1760.html

Tuesday, September 14, 2010

NASA Uses New Method to Estimate Earth Mass Movements

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NASA and European researchers have conducted a novel study to simultaneously measure, for the first time, trends in how water is transported across Earth's surface and how the solid Earth responds to the retreat of glaciers following the last major Ice Age, including the shifting of Earth's center of mass.

To calculate the changes, scientists at NASA's Jet Propulsion Laboratory, Pasadena, Calif.; Delft University of Technology, Delft, Netherlands; and the Netherlands Institute for Space Research, Utrecht, Netherlands, combined gravity data from the NASA/German Aerospace Center Gravity Recovery and Climate Experiment satellites with direct measurements of global surface movements from GPS and other sources and a JPL-developed model that estimates the mass of Earth's ocean above any point on the ocean floor. Results are reported in the September issue of Nature Geoscience.

Using the new methodology, the researchers, led by Xiaoping Wu of JPL, calculated new estimates of ice loss in Greenland and Antarctica that are significantly smaller than previous estimates. According to the team's estimates, mass losses between 2002 and 2008 measured 104 (plus or minus 23) gigatonnes a year in Greenland, 101 (plus or minus 23) gigatonnes a year in Alaska/Yukon, and 64 (plus or minus 32) gigatonnes a year in West Antarctica. A gigatonne is one billion metric tons, or more than 2.2 trillion pounds. The smaller but significant ice loss estimates reflect the revised role that post-glacial rebound was found to play in relation to current ice mass loss in Greenland and Antarctica. Post-glacial rebound (known as glacial isostatic adjustment) is the response of the solid Earth to the retreat of glaciers following the last Ice Age. After the weight of ice from the land surface was removed, the land under the ice rose and continues to slowly rise.

In addition, the team found that the shift of water mass around the globe, combined with the post-glacial rebound of Earth's surface, is shifting Earth's surface relative to its center of mass by 0.88 millimeters (.035 inches) a year toward the North Pole. The estimate of the shift due to rebound-0.72 millimeters (.028 inches) per year--is believed to be the first estimate based on actual data, rather than a model prediction.

Wu said the shift of Earth's surface is due primarily to the melted Laurentide ice sheet, which blanketed most of Canada and a part of the northern United States around 21,000 years ago. "The new estimate of shift is much larger than previous model estimates of 0.48 millimeters [.019 inches] per year," said Wu. "This suggests that either Earth's lower mantle must be much more viscous than previously believed, or that the history of Earth's deglaciation needs to be significantly revised."

Wu said previous GRACE-based estimates of the movement of mass at Earth's surface have been calculated by correcting the data using a post-glacial rebound model, while estimates of post-glacial rebound itself have been estimated using a hydrological model. These models are not as precise as the geodetic data, however, and contain unknown and potentially large errors that will throw off estimates of the other process.

GRACE project scientist Michael Watkins of JPL, who was not an author on the paper, said that although some of the new results, such as those for Greenland, are surprising, they are not due to a reanalysis of GRACE or GPS data alone. Rather, they are a result of the simultaneous use of GRACE, GPS and other geodetic measurements to help objectively sort out the relative sizes of post-glacial rebound and present-day ice mass loss. "Both the GPS and gravity measurements are accurate on their own, but untangling the relative contributions of the two processes as observed by satellites is difficult. This technique provides a first global attempt at doing that," Watkins said.

"The Earth system is so complex that measuring and understanding it requires scientists to combine observations from as many satellites and ground-based measurements as possible," Watkins added. "With each new study like this one, we learn more and more about how to conduct future studies and interpret their data. The more data, and different types of data we collect, the better we'll be able to answer fundamental questions about how our planet works."

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-298

Monday, September 13, 2010

ARTEMIS - The First Earth-Moon Libration Orbiter

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In August 1960, NASA launched its first communications satellite, Echo 1. Fifty years later, NASA has achieved another first by placing the ARTEMIS-P1 spacecraft into a unique orbit behind the moon, but not actually orbiting the moon itself. This type of orbit, called an Earth-Moon libration orbit, relies on a precise balancing of the Sun, Earth, and Moon gravity so that a spacecraft can orbit about a virtual location rather than about a planet or moon. The diagrams below show the full ARTEMIS-P1 orbit as it flies in proximity to the moon.


ARTEMIS-P1 is the first spacecraft to navigate to and perform stationkeeping operations around the Earth-Moon L1 and L2 Lagrangian points. There are five Lagrangian points associated with the Earth-Moon system. The two points nearest the moon are of great interest for lunar exploration. These points are called L1 (located between the Earth and Moon) and L2 (located on the far side of the Moon from Earth), each about 61,300 km (38,100 miles) above the lunar surface. It takes about 14 to 15 days to complete one revolution about either the L1 or L2 point. These distinctive kidney-shaped orbits are dynamically unstable and require weekly monitoring from ground personnel. Orbit corrections to maintain stability are regularly performed using onboard thrusters.

After the ARTEMIS-P1 spacecraft has completed its first four revolutions in the L2 orbit, the ARTEMIS-P2 spacecraft will enter the L1 orbit. The two sister spacecraft will take magnetospheric observations from opposite sides of the moon for three months, then ARTEMIS-P1 will move to the L1 side where they will both remain in orbit for an additional three months. Flying the two spacecraft on opposite sides, then the same side, of the moon provides for collection of new science data in the Sun-Earth-Moon environment. ARTEMIS will use simultaneous measurements of particles and electric and magnetic fields from two locations to provide the first three-dimensional perspective of how energetic particle acceleration occurs near the Moon's orbit, in the distant magnetosphere, and in the solar wind. ARTEMIS will also collect unprecedented observations of the space environment behind the dark side of the Moon – the greatest known vacuum in the solar system – by the solar wind. In late March 2011, both spacecraft will be maneuvered into elliptical lunar orbits where they will continue to observe magnetospheric dynamics, solar wind and the space environment over the course of several years.

ARTEMIS stands for “Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon’s Interaction with the Sun”. The ARTEMIS mission uses two of the five in-orbit spacecraft from another NASA Heliophysics constellation of satellites (THEMIS) that were launched in 2007 and successfully completed their mission earlier this year. The ARTEMIS mission allowed NASA to repurpose two in-orbit spacecraft to extend their useful science mission, saving tens of millions of taxpayer dollars instead of building and launching new spacecraft. Other benefits of this first ever libration orbit mission include the investigation of lunar regions to provide a staging location for both assembly of telescopes or human exploration of planets and asteroids or even to serve as a communication relay location for a future lunar outpost. The navigation and control of the spacecraft will also provide NASA engineers with important information on propellant usage, requirements on ground station resources, and the sensitivity of controlling these unique orbits.

The ARTEMIS mission implementation and operation represents a joint effort between NASA Goddard Space Flight Center in Greenbelt, Md., the Jet Propulsion Laboratory in Calif., and the University of California, Berkeley, Space Sciences Laboratory.

For more information visit http://www.nasa.gov/mission_pages/themis/news/artemis-orbit.html

Sunday, September 12, 2010

NASA Goddard Receives the Webb Telescope's Guiding Light from Canada

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An engineering test unit of the Fine Guidance Sensor is about to undergo cryogenic testing at the David Florida Lab in Canada

The Canadian Space Agency has delivered a test unit of the Fine Guidance Sensor to the James Webb Space Telescope to NASA's Goddard Space Flight Center in Greenbelt, Md.

The arrival of the engineering test unit marks a major milestone for the Canadian team. The hardware has been put through its paces at the Canadian Space Agency's David Florida Lab to ensure that the final version will function at peak performance. While all space missions undergo extensive testing, this step is particularly crucial for Webb because it will be located at the L2 point in space, which is about 930,000 miles away from the Earth in the exact opposite direction from the sun, and too far to be serviced by astronauts.

Scott Lambros, Webb telescope instrument systems manager at NASA Goddard said, "The delivery of the Fine Guidance Sensor (FGS) Engineering Test Unit is another milestone towards launch of the Webb telescope. In the coming months we will use the ETU to test interfaces between the FGS instrument and the Webb Observatory, to ensure that any discrepancies will be accounted for in the flight versions of the hardware." Just as important, the milestone is an indication of the great working relationship we have between NASA and the CSA/COM DEV team. "It's been a joy working with this group of people. I look forward to continuing that work to the next milestone of delivery of the flight model FGS next year," Lambros said.

The Fine Guidance Sensor consists of two specialized cameras that are critical to Webb’s ability to "see": they will work like a guiding scope to allow the Webb space telescope to locate its celestial targets, determine its own position and remain pointed at an object so that the telescope can collect high-quality data. The FGS will measure the position of guide stars with incredible precision, pinpointing them with an accuracy of one millionth of a degree. The angle formed by someone holding up a quarter at a distance of 930 miles away, which is almost as far from Boston to Chicago.

In addition to providing the Webb telescope’s Fine Guidance Sensor (FGS), the Canadian Space Agency will also provide the Tunable Filter Imager (TFI). Both actual instruments are also being built by COM DEV International for the Canadian Space Agency.

The TFI’s unique capabilities will allow astronomers to peer through clouds of dust to see stars forming and planetary systems, possibly even exoplanets (planets outside our Solar System). It also offers unique capability to find the earliest objects in the Universe’s history. The Canadian Project Scientist for Webb is Dr. John Hutchings of the National Research Council of Canada. Dr. René Doyon of the Université de Montréal is the principal investigator for TFI. Canada is also providing functional support of the science operations for the Webb space telescope. The Canadian Space Agency will deliver the flight units of the FGS and the TFI to NASA in 2011.

Webb will be the first next-generation large space observatory and will serve thousands of astronomers worldwide for a planned lifetime of 10 years or more. Designed to detect light from as far away as approximately 14 billion light years, it will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System. Its advanced technology also enables it to discover hitherto unknown phenomena in the Universe.

The Webb telescope is an international collaboration between NASA, the European Space Agency and the Canadian Space Agency.

For more information visit http://www.nasa.gov/topics/technology/features/fgs-testing.html

Thursday, September 9, 2010

NASA Data Shed New Light About Water and Volcanoes on Mars

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Data from NASA's Phoenix Mars Lander suggest liquid water has interacted with the Martian surface throughout the planet's history and into modern times. The research also provides new evidence that volcanic activity has persisted on the Red Planet into geologically recent times, several million years ago.

Although the lander, which arrived on Mars on May 25, 2008, is no longer operating, NASA scientists continue to analyze data gathered from that mission. These recent findings are based on data about the planet's carbon dioxide, which makes up about 95 percent of the Martian atmosphere.

"Atmospheric carbon dioxide is like a chemical spy," said Paul Niles, a space scientist at NASA's Johnson Space Center in Houston. "It infiltrates every part of the surface of Mars and can indicate the presence of water and its history."

Phoenix precisely measured isotopes of carbon and oxygen in the carbon dioxide of the Martian atmosphere. Isotopes are variants of the same element with different atomic weights. Niles is lead author of a paper about the findings published in Thursday's online edition of the journal Science. The paper explains the ratios of stable isotopes and their implications for the history of Martian water and volcanoes.

"Isotopes can be used as a chemical signature that can tell us where something came from, and what kinds of events it has experienced," Niles said.

This chemical signature suggests that liquid water primarily existed at temperatures near freezing and that hydrothermal systems similar to Yellowstone's hot springs have been rare throughout the planet's past. Measurements concerning carbon dioxide showed Mars is a much more active planet than previously thought. The results imply Mars has replenished its atmospheric carbon dioxide relatively recently, and the carbon dioxide has reacted with liquid water present on the surface.

Measurements were performed by an instrument on Phoenix called the Evolved Gas Analyzer. The instrument was capable of doing more accurate analysis of carbon dioxide than similar instruments on NASA's Viking landers in the 1970s. The Viking Program provided the only previous Mars isotope data sent back to Earth.

The low gravity and lack of a magnetic field on Mars mean that as carbon dioxide accumulates in the atmosphere, it will be lost to space. This process favors loss of a lighter isotope named carbon-12 compared to carbon-13. If Martian carbon dioxide had experienced only this process of atmospheric loss without some additional process replenishing carbon-12, the ratio of carbon-13 to carbon-12 would be much higher than what Phoenix measured. This suggests the Martian atmosphere recently has been replenished with carbon dioxide emitted from volcanoes, and volcanism has been an active process in Mars' recent past. However, a volcanic signature is not present in the proportions of two other isotopes, oxygen-18 and oxygen-16, found in Martian carbon dioxide. The finding suggests the carbon dioxide has reacted with liquid water, which enriched the oxygen in carbon dioxide with the heavier oxygen-18.

Niles and his team theorize this oxygen isotopic signature indicates liquid water has been present on the Martian surface recently enough and abundantly enough to affect the composition of the current atmosphere. The findings do not reveal specific locations or dates of liquid water and volcanic vents, but recent occurrences of those conditions provide the best explanations for the isotope proportions.

The Phoenix mission was led by principal investigator Peter H. Smith of the University of Arizona in Tucson, with project management at NASA's Jet Propulsion Laboratory in Pasadena, Calif. JPL is a division of the California Institute of Techology in Pasadena. The University of Arizona provided the lander's Thermal and Evolved Gas Analyzer.

For moreinformation visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-294

Wednesday, September 8, 2010

NASA Satellites Reveal Surprising Connection Between Beetle Attacks, Wildfire

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If your summer travels have taken you across the Rocky Mountains, you've probably seen large swaths of reddish trees dotting otherwise green forests. While it may look like autumn has come early to the mountains, evergreen trees don't change color with the seasons. The red trees are dying, the result of attacks by mountain pine beetles.

Mountain pine beetles are native to western forests, and they have evolved with the trees they infest, such as lodgepole pine and whitebark pine trees. However, in the last decade, warmer temperatures have caused pine beetle numbers to skyrocket. Huge areas of red, dying forest now span from British Columbia through Colorado, and there's no sign the outbreak is slowing in many areas.

The affected regions are so large that NASA satellites, such as Landsat, can even detect areas of beetle-killed forest from space. Today, NASA has released a new video about how scientists can use Landsat satellite imagery to map these pine beetle outbreaks, and what impact the beetle damage might have on forest fire.

As the dog days of summer hit full force, some say the pine beetles have transformed healthy forest into a dry tinderbox primed for wildfire.

For Yellowstone National Park Vegetation Management Specialist Roy Renkin, those worries are nothing new. "I've heard [the tinderbox analogy] ever since I started my professional career in the forestry and fire management business 32 years ago," he said. "But having the opportunity to observe such interaction over the years in regards to the Yellowstone natural fire program, I must admit that observations never quite met with the expectation."

The idea that beetle damaged trees increase fire risks seems a logical assumption – dead trees appear dry and flammable, whereas green foliage looks more moist and less likely to catch fire. But do pine beetles really increase the risk of fire in lodgepole pine forest? University of Wisconsin forest ecologists Monica Turner and Phil Townsend, in collaboration with Renkin, are studying the connection in the forests near Yellowstone National Park. Their work -- and their surprising preliminary results -- are the subject of the NASA video.

First, the researchers used Landsat data to create maps of areas hardest hit by the recent beetle outbreak. The Landsat satellites capture imagery not just in the visible spectrum, but also in wavelengths invisible to the human eye. One such wavelength band combination includes the near infrared, a part of the spectrum in which healthy plants reflect a great deal of energy. By scanning the Landsat near infrared imagery, the team located areas of probable beetle damage.

Next, they hiked into the areas to confirm that the majority of the affected trees were indeed killed by beetles rather than by other causes. Mountain pine beetles leave telltale signs of their presence, including "pitch tubes" -- areas of hardened resin where trees attempt to defend themselves from the boring insects by flowing sticky pitch from the wounds. By scanning the trees for pitch tubes and looking for beetle "galleries" under the bark where the adult insect lays its eggs, the team was able to confirm that they were reading the satellite imagery correctly.

Finally, the University of Wisconsin team compares maps of beetle-killed forest with maps of recent fires.

"Of course, we can't go out and actually set a fire in beetle damaged areas where we've got red, green or no needles," Townsend said. We just can't do that, so we collect data on the ground, we collect data from satellites, and then we build models of how much fuel is there and how burnable it is."

Their preliminary analysis indicates that large fires do not appear to occur more often or with greater severity in forest tracts with beetle damage. In fact, in some cases, beetle-killed forest swaths may actually be less likely to burn. What they're discovering is in line with previous research on the subject.

The results may seem at first counterintuitive, but make sense when considered more carefully. First, while green needles on trees appear to be more lush and harder to burn, they contain high levels very flammable volatile oils. When the needles die, those flammable oils begin to break down. As a result, depending on the weather conditions, dead needles may not be more likely to catch and sustain a fire than live needles.

Second, when beetles kill a lodgepole pine tree, the needles begin to fall off and decompose on the forest floor relatively quickly. In a sense, the beetles are thinning the forest, and the naked trees left behind are essentially akin to large fire logs. However, just as you can't start a fire in a fireplace with just large logs and no kindling, wildfires are less likely to ignite and carry in a forest of dead tree trunks and low needle litter.

Forest ecologists noted this same phenomenon after the massive Yellowstone wildfires in 1988. As large crown fires swept quickly through the forest, many trees were killed and their needles burned off, but the standing dead tree trunks remained. In the ensuing years, new wildfires have tended to slow and sometimes even burn out when they reach standing dead forest. There simply aren't enough small fuels to propel the fire.

For Townsend, the results are a further reminder that, in complex ecosystems like that in and around Yellowstone, things aren't always as they appear at first blush.

"I think it's important for people not to assume that there are relationships for certain types of features on the landscape," he says. "It's easy to think, 'It's more damaged so more likely to burn.' That's why it's important to ask questions and not take everything as gospel truth, but go out and see if what we think is happening in our mind is really happening on the ground."

While pine beetle attacks may not, in fact, increase fire risk in western forests, Townsend believes fire and beetles do share a connection -- climate change.

Cold winter nights have traditionally kept beetle numbers in check by killing off larvae as they overwinter in trees. In the last decade, winter nighttime temperatures have not dipped as low -- an observation predicted by climate change models. More beetles are surviving to damage larger areas of forest.

Fires, of course, are also affected by warmer temperatures. As temperatures warm and some areas become drier, many climate scientists predict fires to increase in number and size.

Both hold the potential to significantly change Rocky mountain forests, but, as Townsend noted, both are also key to forest health.

"Both fire and beetle damage are natural parts of system and have been since forests developed," Townsend said. "What we have right now is a widespread attack that we haven't seen before, but it is a natural part of the system."

Renkin agrees with the assessment. "Disturbances like insect outbreaks and fire are recognized to be integral to the health of the forests," he said, "and it has taken ecologists most of this century to realize as much. Yet when these disturbances occur, our emotional psyche leads us to say the forests are 'unhealthy.' Bugs and fires are neither good nor bad, they just are."

The Rocky Mountain West has experienced relatively few large fires this year, but the fire season isn't over yet. The end of the current pine beetle outbreak is likely even further away.

As a result, future summer travelers are likely to see more of these two Rocky mountain natives -- mountain pine beetles and fire.

Landsat is a joint program of NASA and the U.S. Geological Survey.

For more information visit http://www.nasa.gov/topics/earth/features/beetles-fire.html

Tuesday, September 7, 2010

Cassini Captures a Divine Dione

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Cruising past Saturn's moon Dione this past weekend, NASA's Cassini spacecraft got its best look yet at the north polar region of this small, icy moon and returned stark raw images of the fractured, cratered surface.

The new images also show new views of the long, bright canyon ice walls, which scientists working with NASA's Voyager spacecraft called "wispy terrain" in the early 1980s. These ice walls thread along the surface of the moon's trailing hemisphere and cut across craters.

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

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-290

Monday, September 6, 2010

ATHLETE Rover Steps Up to Long Desert Trek

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The ATHLETE rover, currently under development at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is in the Arizona desert this month to participate in NASA's Research and Technology Studies, also known as Desert RATS. The desert tests offer a chance for a NASA-led team of engineers, astronauts and scientists from across the country to test concepts for future missions.

NASA will demonstrate a variety of hardware during this year's test, including:

-- All-Terrain Hex-Legged Extra-Terrestrial Explorers (ATHLETE): two heavy-lift rover platforms that allow a habitat, or other large items, to go where the action is.
-- Space Exploration Vehicles: two rovers astronauts could live in for seven days at a time.
-- Habitat Demonstration Unit/Pressurized Excursion Module: a simulated habitat where the rovers can dock to allow the crew room to perform experiments or deal with medical issues.
-- Portable Communications Terminal: a rapidly deployable communications station.
-- Centaur 2: a four-wheeled possible transportation method for NASA Robonaut 2.
-- Portable Utility Pallets: mobile charging stations for equipment.
-- A suite of new geology sample collection tools, including a self-contained GeoLab glove box for conducting in-field analysis of various collected rock samples.

The public was involved in test preparation by helping NASA decide what areas should be explored. NASA posted several possibilities online and allowed members of the public to vote on the most promising locations. Several thousand ballots were cast and 67 percent favored a location that appeared to be home of several overlapping lava flows.

NASA centers involved in the Desert RATS tests include Johnson Space Center in Houston; Langley Research Center in Va.; JPL; Ames Research Center, Moffett Field, Calif.; Kennedy Space Center in Florida; Goddard Space Flight Center in Maryland; Glenn Research Center in Cleveland; Marshall Space Flight Center in Alabama; and NASA Headquarters in Washington.

In addition, professors and students from various universities, as well as the Canadian Space Agency, are participating in the Desert RATS field tests.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-287

Sunday, September 5, 2010

Next Mars Rover Stretches Robotic Arm

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Curiosity, the Mars Science Laboratory rover that will be on Mars two years from now, has been flexing the robotic arm that spacecraft workers at NASA's Jet Propulsion Laboratory attached to the rover body in August 2010.

The arm will be crucial for putting samples of soil or powdered rock into analytical instruments inside the rover. A camera and spectrometer to be installed at the end of the arm will also examine rocks and soils in place.

The Mars Science Laboratory will launch from Florida in November or December 2011 and land in August 2012 at one of the most intriguing sites on Mars. The landing site is still to be chosen from four finalists. Once on Mars, Curiosity will study whether the landing region has ever had environmental conditions favorable for life and favorable for preserving evidence of life if it existed.

Thursday, September 2, 2010

NASA Hurricane Researchers Eye Earl's Eye

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Hurricane Earl, currently a Category Two storm on the Saffir-Simpson scale with maximum sustained winds of 100 knots (115 miles per hour), continues to push relentlessly toward the U.S. East Coast, and NASA scientists, instruments and spacecraft are busy studying the storm from the air and space. Three NASA aircraft carrying 15 instruments are busy criss-crossing Earl as part of the agency's Genesis and Rapid Intensification Processes mission, or GRIP, which continues through Sept. 30. GRIP is designed to help improve our understanding of how hurricanes such as Earl form and intensify rapidly.

Among the instruments participating in GRIP is the High-Altitude Monolithic Microwave Integrated Circuit Sounding Radiometer, or HAMSR, developed by NASA's Jet Propulsion Laboratory, Pasadena, Calif. The instrument, which flies aboard NASA's Global Hawk uninhabited aerial vehicle, infers the 3-D distribution of temperature, water vapor and cloud liquid water in the atmosphere.

The Global Hawk left NASA's Dryden Flight Research Center, Edwards, Calif., at 9 p.m. PDT on Sept. 1, and emerged off the coast of Florida seven hours later to begin its first-ever flight over a hurricane. The plane spent the day today flying over Earl and is returning to Dryden tonight. An image of Earl as seen the morning of Sept. 2 from a high-definition camera aboard the Global Hawk is shown in Figure 3.

HAMSR has been able to make multiple passes straight across Earl's eye. Figure 1 shows brightness temperature data collected by HAMSR over a half-hour sequence of overpasses around 3 p.m. EDT on Sept. 2. The Global Hawk was flying at an altitude of about 19.2 kilometers (63,000 feet) approximately 1,125 kilometers (700 miles) off Florida's east coast. Earl's eye is visible as the blue-green circular area in the center of the image, surrounded by orange-red. The eye is colored blue-green because the instrument is seeing the ocean surface, which appears cool to the instrument. The surrounding clouds appear warm because they shield the cooler ocean surface from view. Just north of the ring of clouds is a deep blue arch, which represents a burst of convection (intense thunderstorms). The pink crosses in the image represent lightning in the area, as measured by a lightning network. Ice particles and heavy precipitation in the convective storm cell cause it to appear cold.

This image illustrates many of the capabilities of HAMSR, from measuring sea surface and atmospheric temperature to measuring convection and precipitation. For example, since there is a clear view of Earl's eye down to the ocean surface, scientists can determine the change of atmospheric temperatures at different altitudes within the eye, an indication of the strength of convection in the core of the storm. This warming is due to the condensation of water vapor that has been lofted to higher altitudes by the strong convection. This is the engine that powers the storm. That temperature data, in turn, can be used to estimate the intensity of the hurricane. NOAA's National Hurricane Center is currently using this method to determine hurricane intensity.

A second JPL instrument participating in GRIP and flying over Earl is the Airborne Precipitation Radar (APR-2), a dual-frequency weather radar that is taking 3-D images of precipitation aboard NASA's DC-8 aircraft. APR-2 is being used to help scientists understand the processes at work in hurricanes by looking at the vertical structure of the storms.

The two APR-2 images that make up Figure 2 reveal the early evolution of Hurricane Earl from a rather disorganized storm (left) to a better developed hurricane with a more distinct and smaller eye and sharper eyewall (right). The data, taken during southbound passes over Earl's eye on Aug. 29 and 30, respectively, are essentially vertical slices of the storm. They correspond to the intensity of precipitation seen by the radar along the DC-8's flight track. Intense convective precipitation (shown in shades of red and pink) was observed on both sides of the hurricane's eye. The eye is indicated by the dark region near the middle of the images. The yellow-green-colored regions indicate areas of lighter precipitation. The white lines near the bottom are the ocean surface.

The progress of NASA's GRIP aircraft can be followed in near-real-time when they are flying by visiting: http://grip.nsstc.nasa.gov/current_weather.html. "Click to start RTMM Classic" will download a KML file that displays in Google Earth.

Near-real-time images from HAMSR and APR-2 are being displayed on NASA's TC-IDEAS . The website is a near-real-time tropical cyclone data resource developed by JPL to support the GRIP campaign. In collaboration with other institutions, it integrates data from satellites, models and direct measurements, from many sources, to help researchers quickly locate information about current and recent oceanic and atmospheric conditions. The composite images and data are updated every hour and are displayed using a Google Earth plug-in. With a few mouse clicks, users can manipulate data and overlay multiple data sets to provide insights on storms that aren't possible by looking at single data sets alone.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-285

Wednesday, September 1, 2010

Herschel Finds Water in a Cosmic Desert

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The Herschel infrared space observatory has discovered that ultraviolet starlight is the key ingredient for making water in space. It is the only explanation for why a dying star is surrounded by a gigantic cloud of hot water vapor. Herschel is a European Space Agency mission with important participation from NASA.

Every recipe needs a secret ingredient. When astronomers discovered an unexpected cloud of water vapor around the old star IRC+10216 using NASA's Submillimeter Wave Astronomy Satellite in 2001, they immediately began searching for the source. Stars like IRC+10216 are known as carbon stars and are thought not to make much water. Initially they suspected the star's heat must be evaporating comets or even dwarf planets to produce the water.

Now, Herschel has revealed that the secret ingredient is ultraviolet light, because the water is too hot to have come from the destruction of icy celestial bodies.

"Models predict that there should be no water in the envelopes around stars like this, so astronomers were puzzled about how it got there," said Paul Goldsmith, the NASA project scientist for Herschel at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "These Herschel observations confirm the surprising presence of water vapor in what we thought was an astronomical desert."

This research, which was led by Leen Decin of the Katholieke Universiteit Leuven, Belgium, appears in the Sept. 2 issue of Nature.

Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes and with important participation by NASA. NASA's Herschel Project Office is based at JPL. JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the United States astronomical community. Caltech manages JPL for NASA.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-281