Galactic Super-Volcano in Action

This image shows the eruption of a galactic “super-volcano” in the massive galaxy M87, as witnessed by NASA's Chandra X-ray Observatory and NSF's Very Large Array (VLA). At a distance of about 50 million light years, M87 is relatively close to Earth and lies at the center of the Virgo cluster, which contains thousands of galaxies.

The cluster surrounding M87 is filled with hot gas glowing in X-ray light (and shown in blue) that is detected by Chandra. As this gas cools, it can fall toward the galaxy's center where it should continue to cool even faster and form new stars.

However, radio observations with the VLA (red) suggest that in M87 jets of very energetic particles produced by the black hole interrupt this process. These jets lift up the relatively cool gas near the center of the galaxy and produce shock waves in the galaxy's atmosphere because of their supersonic speed.

The interaction of this cosmic “eruption” with the galaxy's environment is very similar to that of the Eyjafjallajokull volcano in Iceland that occurred in 2010. With Eyjafjallajokull, pockets of hot gas blasted through the surface of the lava, generating shock waves that can be seen passing through the grey smoke of the volcano. This hot gas then rises up in the atmosphere, dragging the dark ash with it. This process can be seen in a movie of the Eyjafjallajokull volcano where the shock waves propagating in the smoke are followed by the rise of dark ash clouds into the atmosphere.

In the analogy with Eyjafjallajokull, the energetic particles produced in the vicinity of the black hole rise through the X-ray emitting atmosphere of the cluster, lifting up the coolest gas near the center of M87 in their wake. This is similar to the hot volcanic gases drag up the clouds of dark ash. And just like the volcano here on Earth, shockwaves can be seen when the black hole pumps energetic particles into the cluster gas. The energetic particles, coolest gas and shockwaves are shown in a labeled version.

Credits: X-ray: NASA/CXC/KIPAC/N. Werner et al Radio: NSF/NRAO/AUI/W. Cotton

For more information visit http://www.nasa.gov/mission_pages/chandra/multimedia/photo10-110.html

NASA Video Shows Global Reach of Pollution from Fires

A series of large wildfires burning across western and central Russia, eastern Siberia and western Canada has created a noxious soup of air pollution that is affecting life far beyond national borders. Among the pollutants created by wildfires is carbon monoxide, a gas that can pose a variety of health risks at ground level. Carbon monoxide is also an ingredient in the production of ground-level ozone, which causes numerous respiratory problems. As the carbon monoxide from these wildfires is lofted into the atmosphere, it becomes caught in the lower bounds of the mid-latitude jet stream, which swiftly transports it around the globe.

Two movies were created using continuously updated data from the "Eyes on the Earth 3-D" feature on NASA's global climate change website http://climate.nasa.gov/ . They show three-day running averages of daily measurements of carbon monoxide present at an altitude of 5.5 kilometers (18,000) feet, along with its global transport. The data are from the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua spacecraft. AIRS is most sensitive to carbon monoxide at this altitude, which is a region conducive to long-range transport of the smoke. The abundance of carbon monoxide is shown in parts per billion, with the highest concentrations shown in yellows and reds.

The first movie, centered over Moscow, highlights the series of wildfires that continue to burn across Russia. It covers the period between July 18 and Aug. 10, 2010.

The second movie is centered over the North Pole and covers the period from July 16 to Aug. 10, 2010. From this vantage point, the long-range transport of pollutants is more easily visible.

AIRS is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

More information about AIRS can be found at http://airs.jpl.nasa.gov .

For more information visit http://www.nasa.gov/topics/earth/features/earth20100811.html

Ping-Pong Balls to Float Crew Capsule Simulator

If ping-pong balls can float a sunken boat, they should be able to keep an uncrewed space capsule simulator from sinking.

Right?

That's what a team of summer students and engineers think at NASA's Langley Research Center in Hampton, Va. Langley is fabricating a proposed design of an astronaut crew module simulator for uncrewed flight-testing as part of the agency's effort to build a vehicle to replace the space shuttle.

The Orion crew exploration vehicle is the nation's next generation spacecraft designed to carry up to four astronauts to low Earth orbit and beyond.

Orion's first suborbital flight test will launch to 400,000 feet, or 75 miles above Earth. Because the crew module will not be pressurized during the test, it will not have the buoyancy of a pressurized spacecraft. This puts the simulated crew module at risk of sinking to the bottom of the Atlantic Ocean after splashdown.

To save the valuable test article for analysis and possible reuse, Langley called on a team of creative minds for a solution.

NASA Langley students gather around the crew module mockup that they propose to keep afloat with ping-pong balls after it splashes down. From left, front row: Edward Tillistrand, Brice Collamer, Patrick Cragg, Caroline Kirk and Kurian Thomas. In the capsule, from left; Joseph Randall Hunt, Heather Blount and Victor Stewart. Credit: NASA/Sean Smith

And as it turned out, inexpensive, lightweight ping-pong balls provided the answer. Langley engineer John DiNonno proposed the idea, and the Orion Flight Test Office told the team to study it.

The idea quickly became "very plausible," said student Caroline Kirk.

Way to go

"At first we didn't really realize that we were going to get so far in proving that it would be possible," said Kirk, a Suffolk, Va., native attending Virginia Tech as an aerospace engineering major. "But when we thought about everything logically, it just seemed like ping-pong balls were the way to go."

She and a team of seven other students worked the project in Langley's Mechanical Systems Branch, where they were assigned for the summer.

DiNonno got the idea from a Discovery Channel program about raising a sunken boat using 27,000 ping-pong balls.

Engineer David Covington said that when DiNonno suggested the ping-pong ball idea, "I just laughed. Not a 'what are you thinking' kind of laugh, but more of a 'that's the most awesome thing I've heard in a long time' laugh. I asked him 'are you serious?' and he said 'yeah, we're authorized to do a four-week study.' So we went straight to work."

Ensuring the outcome would be relatively low-cost was a top priority, said DiNonno.

"Recovering the capsule was not a requirement, but it was a desire," he said. "So there wasn't going to be a lot of investment in it."

Testing process

The students divided the tasks needed to determine if the idea was feasible, each becoming a "principal investigator" for a specific area.

They tested ping-pong balls of varying quality, much the way spacecraft hardware is tested. They studied how the balls would react to the near-vacuum at the edge of space. Using buoyancy tests, they determined how well the balls would float.

The students also subjected the ping-pong balls to mechanical loads using a hydraulic press, and heated them to see how they would react to the high temperatures of descent into the Earth's atmosphere. And they performed electrostatic discharge tests to determine if the balls would produce a static charge that could disrupt the space capsule's electronics.

Ping-Pong Ball Facts

›› Ping-pong balls are made of celluloid, which is processed cotton.
›› Each ping-pong ball weighs less than an ounce (2.7 grams) and is roughly 1.5 inches (38 - 40 mm) in diameter.
›› Ping-pong ball quality is rated from zero to three stars.

Credit: Microsoft

The ping-pong balls passed all the challenges, said Heather Blount, a materials science engineering student at Virginia Tech.

"Through all our testing and calculations, we figured out that it could be a safe and viable option," said Blount, of Yorktown, Va.

Keeping the crew module afloat would take at least 150,000 ping-pong balls, the students estimate, at a retail price of 50 cents or less each -- a fraction of the cost of traditional options. The students hope to reduce the cost through a bulk purchase.

If the flight test is approved, the ping-pong ball concept would still need to be vetted with the flight test team and reviewed by NASA senior management. If implemented, the ping-pong balls probably will be put into netted bags and secured inside the crew module just prior to launch. They would virtually fill the available space inside the uncrewed capsule.

Then, when the unsealed capsule splashes down, the buoyancy of the ping-pong balls will offset the weight of incoming water and it will float instead of sink.

The ping-pong balls also will reduce the volume of air that needs to be vented from the capsule during ascent - as well as drawn in during descent - as the capsule travels through significant changes in atmospheric pressure.

'Awesome' students

Approval of the flight test, as well as a launch date, has yet to be determined. "Even if it is not used, it's an idea that's out there that someone else could use," said Langley engineer Amanda Cutright, a student mentor.

Cutright said she has been enthused by the students.

"It's awesome working with them," she said. "They bring a different perspective. I've been really impressed with how quickly they pick up new ideas and new technology. It seems each team of students that we mentor learns quicker and is able to provide creative ideas."

Yammer

The ping-pong ball team has been using a social media tool called Yammer to communicate with each other, share files, links, work status, questions, and solutions.

"Yammer has been a great tool to communicate with the interns," said Brendan Shaughnessy, an engineer in the Mechanical Systems Branch. "They can post updates on their work or links to websites they found. I can also let them all know about something I need them to do or that I've done in one quick message."

To join NASA's Yammer site, you must have an email address that ends in nasa.gov.

The Orion FTA Students site is open to anyone with a NASA Yammer account.

Credit: Yammer.com

Kirk said the ping-pong ball project has been a unique experience. At school, she said, "we do lab experiments but nothing similar to this at all. Being able to develop an experiment that will be used for space flight tests is an opportunity of a lifetime."

NASA employees and contractors involved in the project include engineers Amanda Cutright; Brendan Shaughnessy, Analytical Services and Materials Inc.; David Covington, ATK Space Systems Inc.; and John DiNonno, all of the Mechanical Systems Branch.

Student team members:

Brice Collamer, Virginia Tech, Langley Aerospace Research Summer Scholars (LARSS) program
→ Principal investigator for electrostatic discharge tests
Patrick Cragg, Princeton University, DEVELOP program
→ Principal investigator for further testing and research
Kurian Thomas, University of Virginia, DEVELOP program
→ Principal investigator for loading tests and cost analysis
Caroline Kirk, Virginia Tech, LARSS
→ Co-principal investigator for vacuum oven tests
Joseph Randall Hunt, Western Carolina University, Undergraduate Student Research Program
→ Principal investigator for packing efficiency tests and operations concerns
Heather Blount, Virginia Tech, LARSS
→ Co-principal investigator for vacuum oven tests
Edward Tillistrand, University of Virginia, DEVELOP program
→ Principal investigator for buoyancy tests and quantity analysis
Victor Stewart, Virginia Tech, Cooperative Education Program
→ Principal investigator for support and review of experiment work

For more information visit http://www.nasa.gov/mission_pages/constellation/orion/orionfta-pingpong.html

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IBEX Spacecraft Finds Discoveries Close to Home

Imagine floating 35,000 miles above the sunny side of Earth. Our home planet gleams below, a majestic whorl of color and texture. All seems calm around you. With no satellites or space debris to dodge, you can just relax and enjoy the black emptiness of space.

But looks can be deceiving.

In reality, you've unknowingly jumped into an invisible mosh pit of electromagnetic mayhem — the place in space where a supersonic "wind" of charged particles from the Sun crashes head-on into the protective magnetic bubble that surrounds our planet. Traveling at a million miles per hour, the solar wind's protons and electrons sense Earth's magnetosphere too late to flow smoothly around it. Instead, they're shocked, heated, and slowed almost to a stop as they pile up along its outer boundary, the magnetopause, before getting diverted sideways.

Space physicists have had a general sense of these dynamic goings-on for decades. But it wasn't until the advent of the Interstellar Boundary Explorer or IBEX, a NASA spacecraft launched in October 2008, that they've been able to see what the human eye cannot: the first-ever images of this electromagnetic crash scene. They can now witness how some of the solar wind's charged particles are being neutralized by gas escaping from Earth's atmosphere.

A New Way to See Atoms

IBEX wasn't designed to keep tabs on Earth's magnetosphere. Instead, its job is to map interactions occurring far beyond the planets, 8 to 10 billion miles away, where the Sun's own magnetic bubble, the heliosphere, meets interstellar space.

IBEX found that Energetic Neutral Atoms, or ENAs, are coming from a region just outside Earth's magnetopause where nearly stationary protons from the solar wind interact with the tenuous cloud of hydrogen atoms in Earth's exosphere. Credit: NASA/Goddard Space Flight Center

Only two spacecraft, Voyagers 1 and 2, have ventured far enough to probe this region directly. IBEX, which travels in a looping, 8-day-long orbit around Earth, stays much closer to home, but it carries a pair of detectors that can observe the interaction region from afar.

Here's how: When fast-moving protons in the solar wind reach the edge of the heliosphere, they sometimes grab electrons from the slower-moving interstellar atoms around them, like batons getting passed between relay runners. This charge exchange creates electrically neutral hydrogen atoms that are no longer controlled by magnetic fields. Suddenly, they're free to go wherever they want — and because they're still moving fast, they quickly zip away from the interstellar boundary in all directions.

> Download video

This animation shows a neutral solar particle's path leaving the Sun, following the magnetic field lines out to the Heliosheath. The solar particle hits a hydrogen atom, stealing it's electron and we follow it until we see it hit one of IBEXs detectors. Credit: NASA/Goddard Space Flight Center

Some of these "energetic neutral atoms," or ENAs, zip past Earth, where they're recorded by IBEX. Its two detectors don't take pictures with conventional optics. Instead, they record the number and energy of atoms arriving from small spots of sky about 7 degrees across (the apparent size of a tennis ball held at arm's length). Because its spin axis always points at the Sun, the spacecraft slowly turns throughout Earth's orbit and its detectors scan overlapping strips that create a complete 360 degrees map every six months.

A Collision Zone Near Earth

Because IBEX is orbiting Earth, it also has a front-row seat for observing the chaotic pileup of solar-wind particles occurring along the "nose" of Earth's magnetopause, about 35,000 miles out. ENAs are created there too, as solar-wind protons wrest electrons from hydrogen atoms in the outermost vestiges of our atmosphere, the exosphere.

Other spacecraft have attempted to measure the density of the dayside exosphere, without much success. NASA's Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft probably detected ENAs from this region a decade ago, but its detectors didn't have the sensitivity to pinpoint or measure the source.

Now, thanks to IBEX, we know just how tenuous the outer exosphere really is. "Where the interaction is strongest, there are only about eight hydrogen atoms per cubic centimeter," explains Stephen A. Fuselier, the Lockheed Martin Space Systems researcher who led the mapping effort. His team's results appear in the July 8 issue of Geophysical Research Letters.

The key observations were made in March and April 2009, when IBEX was located far from Earth — about halfway to the Moon's orbit — and its detectors could scan the region directly in front of the magnetopause. During some of the March observations, the European Space Agency's Cluster 3 spacecraft was positioned just in front of the magnetopause, where it measured the number of deflected solar-wind protons directly. "Cluster played a very important role in this study," Fuselier explains. "It was in the right place at the right time."

Artist concept of the IBEX satellite. Credit: NASA/Goddard Space Flight Center

The new IBEX maps show that the ENAs thin out at locations away from the point of peak intensity. This falloff makes sense, Fuselier says, because Earth's magnetopause isn't spherical. Instead, it has a teardrop shape that's closest to Earth at its nose but farther away everywhere else. So at locations well away from the magnetopause's centerline, even fewer of the exosphere's hydrogen atoms are hanging around to interact with the solar wind. "No exosphere, no ENAs," he explains.

A Versatile Spacecraft

Since its launch, IBEX has also scanned another nearby world, with surprising results. The moon has no atmosphere or magnetosphere, so the solar wind slams unimpeded into its desolate surface. Most of those particles get absorbed by lunar dust. In fact, space visionaries wonder if the moon's rubbly surface has captured enough helium-3, an isotope present in tiny amounts in the Sun's outflow, to serve as a fuel for future explorers.

Yet cosmic chemists have long thought that some solar-wind protons must be bouncing off the lunar surface, becoming ENAs through charge exchange as they do. So does the moon glow in IBEX's scans? Indeed it does, says David J. McComas of Southwest Research Institute in San Antonio, Texas, who serves as the mission's Principal Investigator.

In a report published last year in Geophysical Research Letters, McComas and other researchers conclude that about 10 percent of the solar-wind particles striking the Moon escape to space as ENAs detectable by IBEX. That amounts to roughly 150 tons of recycled hydrogen atoms per year.

Meanwhile, the squat, eight-sided spacecraft continues its primary task of mapping the interactions between the outermost heliosphere and the interstellar medium that lies beyond. McComas and his team are especially eager to learn more about the mysterious and unexpected "ribbon" of ENAs that turned up in the spacecraft's initial all-sky map.

At NASA's Goddard Space Flight Center in Greenbelt, Md., IBEX Mission Scientist Robert MacDowall says the spacecraft should be able to continue its observations through at least 2012. "We weren't sure those heliospheric interactions would vary with time, but they do," he explains, "and it's great that IBEX will be able to record them for years to come."

For more information visit http://www.nasa.gov/mission_pages/ibex/em-crash.html

NASA Instrument Tracks Pollution from Russian Fires

Drought and the worst heat wave Russia has seen in 130 years have sparked a devastating outbreak of wildfires across the nation this summer, primarily in the country's western and central regions. According to wire service reports and Russia's Emergency Situations Ministry, as of Aug. 6, 2010, some 558 fires were burning. The fires have killed at least 52 people, destroyed some 2,000 homes and charred more than 1,796 square kilometers (693 square miles). Russia's capital city of Moscow is currently blanketed in a thick smog, which has curtailed activities and disrupted air traffic. According to the Associated Press, levels of carbon monoxide pollution in Moscow are at an all-time high, four times higher than normal.

The Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua spacecraft is tracking the concentration and transport of carbon monoxide from the Russian fires. The figures presented here show the abundance of carbon monoxide present in the atmosphere at an altitude of 5.5 kilometers (18,000 feet). AIRS is sensitive to carbon monoxide in the mid-troposphere at heights between 2 and 10 kilometers (1.2 and 6.2 miles), with a peak sensitivity at an altitude of approximately 5 kilometers (3.1 miles). This region of Earth's atmosphere is also conducive to the long-range transport of the pollution that is lofted to this altitude.

Top (fig.1) and bottom (fig.2) comparison of carbon monoxide pollution from the series of devastating wildfires burning across central and western Russia, as seen by the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua spacecraft on July 21, 2010 (top) and Aug. 1, 2010 (bottom). The AIRS data show the abundance of carbon monoxide present in the atmosphere at an altitude of 5.5 kilometers (18,000 feet). Image credit: NASA/JPL/Leonid Yurganov, University of Maryland, Baltimore County

As shown in Figure 1, acquired July 21, 2010, the concentration of carbon monoxide from the fires on that date was largely limited to the European part of Russia (western and central Russia). This contrasts dramatically with the data in Figure 2, acquired on August 1, when the carbon monoxide concentration was much higher and the area of the fires had increased significantly. The concentration of carbon monoxide is continuing to grow. According to Aug. 4 NASA estimates, the smoke plume from the fires spans about 3,000 kilometers (1,860 miles) from east to west, approximately the distance from San Francisco to Chicago.

Fig. 3 - Changes in the total amount of carbon monoxide above western Russia, in megatons, through Aug. 1, 2010, as measured by the JPL AIRS instrument on NASA's Aqua spacecraft, are compared with 2002 data from the MOPITT instrument on NASA's Terra spacecraft and data from the year 2009, which saw normal levels of seasonal carbon monoxide. Image credit: NASA/JPL/Leonid Yurganov, University of Maryland, Baltimore County

Figure 3 shows changes in the total amount of carbon monoxide above western Russia in megatons through August 1, 2010 (shown by the red curve). The changes are plotted again the base year of 2009, which saw normal levels of seasonal carbon monoxide. This is contrasted against the year 2002, when peat fires predominated in Russia. The 2002 data are from the Measurements of Pollution in the Troposphere (MOPITT) instrument on NASA's Terra spacecraft. On August 1, 2010, the excess carbon monoxide content almost reached the maximum values seen in 2002. The rate of growth (approximately 0.7 megatons, or 700,000 metric tons, per day) characterizes the rate of emission; the current rate is approximately three times higher than in 2002.

AIRS is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena. More information about AIRS can be found at http://airs.jpl.nasa.gov.

For more information visit http://www.nasa.gov/topics/earth/features/fires20100806.html

Blowing in the Wind: Cassini Helps with Dune Whodunit

The answer to the mystery of dune patterns on Saturn's moon Titan did turn out to be blowing in the wind. It just wasn't from the direction many scientists expected.

Basic principles describing the rotation of planetary atmospheres and data from the European Space Agency's Huygens probe led to circulation models that showed surface winds streaming generally east-to-west around Titan's equatorial belt. But when NASA's Cassini spacecraft obtained the first images of dunes on Titan in 2005, the dunes' orientation suggested the sands – and therefore the winds – were moving from the opposite direction, or west to east.

A new paper by Tetsuya Tokano in press with the journal Aeolian Research seeks to explain the paradox. It explains that seasonal changes appear to reverse wind patterns on Titan for a short period. These gusts, which occur intermittently for perhaps two years, sweep west to east and are so strong they do a better job of transporting sand than the usual east-to-west surface winds. Those east-to-west winds do not appear to gather enough strength to move significant amounts of sand.

A related perspective article about Tokano's work by Cassini radar scientist Ralph Lorenz, the lead author on a 2009 paper mapping the dunes, appears in this week's issue of the journal Science.

"It was hard to believe that there would be permanent west-to-east winds, as suggested by the dune appearance," said Tokano, of the University of Cologne, Germany. "The dramatic, monsoon-type wind reversal around equinox turns out to be the key."

Cassini radar sees sand dunes on Saturn's giant moon Titan (upper photo) that are sculpted like Namibian sand dunes on Earth (lower photo). The bright features in the upper radar photo are not clouds but topographic features among the dunes. Image credit: NASA/JPL - upper photo; NASA/JSC - lower photo

The dunes track across the vast sand seas of Titan only in latitudes within 30 degrees of the equator. They are about a kilometer (half a mile) wide and tens to hundreds of kilometers (miles) long. They can rise more than 100 meters (300 feet) high. The sands that make up the dunes appear to be made of organic, hydrocarbon particles. The dunes' ridges generally run west-to-east, as wind here generally sheds sand along lines parallel to the equator.

Scientists predicted winds in the low latitudes around Titan's equator would blow east-to-west because at higher latitudes the average wind blows west-to-east. The wind forces should balance out, based on basic principles of rotating atmospheres.

Tokano re-analyzed a computer-based global circulation model for Titan he put together in 2008. That model, like others for Titan, was adapted from ones developed for Earth and Mars. Tokano added in new data on Titan topography and shape based on Cassini radar and gravity data. In his new analysis, Tokano also looked more closely at variations in the wind at different points in time rather than the averages. Equinox periods jumped out.

Equinoxes occur twice a Titan year, which is about 29 Earth years. During equinox, the sun shines directly over the equator, and heat from the sun creates upwelling in the atmosphere. The turbulent mixing causes the winds to reverse and accelerate. On Earth, this rare kind of wind reversal happens over the Indian Ocean in transitional seasons between monsoons.

The episodic reverse winds on Titan appear to blow around 1 to 1.8 meters per second (2 to 4 mph). The threshold for sand movement appears to be about 1 meter per second (2 mph), a speed that the typical east-to-west winds never appear to surpass. Dune patterns sculpted by strong, short episodes of wind can be found on Earth in the northern Namib sand seas in Namibia, Africa.

Scientists have used data from the Cassini radar mapper to map the global wind pattern on Saturn's moon Titan using data collected over a four-year period, as depicted in this image. Image credit: NASA/JPL/Space Science Institute

"This is a subtle discovery -- only by delving into the statistics of the winds in the model could this rather distressing paradox be resolved," said Ralph Lorenz, a Cassini radar scientist based at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "This work is also reassuring for preparations for proposed future missions to Titan, in that we can become more confident in predicting the winds which can affect the delivery accuracy of landers, or the drift of balloons."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the Cassini-Huygens mission for NASA's Science Mission Directorate. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries. JPL is a division of the California Institute of Technology in Pasadena.

More Cassini information is available, at http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov.

For more information visit http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20100729.html

Cutting Into Arctic Sea Ice

"Over by the fish, below the soccer field," said ice scientist Bonnie Light, pointing at the Arctic sea ice from the bridge of the U.S. Coast Guard Cutter Healy earlier this month during NASA's ICESCAPE oceanographic mission.

Light, of University of Washington, and other ice scientists crowd around the windows on the bridge of the Healy describing shapes created by the melt ponds on the surface of the Arctic sea ice. They point out everything from unicorns to Volkswagons. But the imaginative morning ritual is serious business; the ice teams are discussing where on the ice to work and planning the logistics of the day’s field work.

Since 1979, satellites have tracked changes to Arctic sea ice extent, showing dramatic declines. On average the ice is losing about 13 percent of its summer coverage each decade and the record low was set in 2007. The decline raises two key questions: Why are these changes happening and what do they mean for Arctic ecosystems, particularly the ocean-dwelling plants -- phytoplankton -- that play an integral role in Earth's carbon cycle?

Chris Polashenski of Dartmouth College (left) and Benny Hopson from the Barrow (Alaska) Arctic Science Consortium bore a hole through sea ice in the Chukchi Sea on July 4. Credit: NASA/Kathryn Hansen

Exploring those questions since last month is the ICESCAPE mission onboard the Healy, which is studying the physics, chemistry and biology of the ocean and sea ice within a changing Arctic. On 12 days scattered throughout the five-week mission, the Healy "parked" amid an ice floe and teams of ice scientists stepped foot on the floating ice for a close up look.

After agreeing on a plan from the bridge, ice scientists on July 9, 2010, readied for work at ice station 10 in the Chukchi Sea. The ship's crane lowered sleds of scientific equipment over the side of the ship and then scientists descended down a steep ramp to the ice where they dispersed and set up equipment.

Coast Guard crew and scientists checked the ice for safety, and then guided a deafening drill through the ice and into the ocean. Researchers deployed instruments above, through and below the drill holes -- scattered strategically across the study site -- to characterize how much light is reflected, absorbed and transmitted by the ice.

The ICESCAPE mission is looking at how Arctic ecology is changing with the changes in ice cover. The Earth is undergoing a grand experiment and scientists want to understand those changes because some of those changes may affect our future.

Surprisingly, polar oceans are rich with life and play a major role in drawing down carbon from the atmosphere. But how will that capability change in an ice-free Arctic? How will the creatures in the sea themselves change? Understanding the connections between the ice and the phytoplankton -- the lower rungs on the food chain -- are key to understanding these changes.

Teams of scientists set up equipment on sea ice near the U.S. Coast Guard icebreaker Healy in the Chukchi Sea on July 4.Credit: NASA/Kathryn Hansen

"From a couple of optical measurements, a lot of thickness measurements, and some melt pond measurements, we can do some calculations and get a 2D map of how much light gets through at different wavelengths, and how much of that light is what's called 'photosynthetically available radiation,' which is the stuff the little algae really like," said Don Perovich of the Cold Regions Research and Engineering Laboratory.

To characterize the ice and its optical properties, researchers begin work on top of the ice. Here, pools of water, or "melt ponds," litter the surface, absorbing more sunlight -- both accelerating melt and passing more of that light along to the ocean below.

Chris Polashenski of Dartmouth College waded onto thin ice supporting a pond, drilled a hole, and measured the ice thickness. Just 30 centimeters of ice separated Polashenski from 150 feet of ocean. In contrast, surrounding ice measured in at an average thickness of 80 centimeters.

ICESCAPE scientists draw on the ship's bridge windows on July 9 as they plan a day of work on sea ice in the Arctic's Chukchi Sea. Credit: NASA/Kathryn Hansen

"The thickness distribution is one of the key parameters of sea ice," Perovich said. "In particular for this experiment it strongly governs how much light gets through into the ocean."

So how much light makes it through these ice thicknesses? To find out, Light worked with her team to collect optical measurements tracking the transmission of light above, inside, and just below the ice at the borehole sites.

Still other groups looked deeper, at both the life forms in the water column below the ice and the light that is sustains them. To gather these snapshots, Karen Frey of Clark University and colleagues dropped an optical sensor down 30 meters, while simultaneously collecting samples of water with Chief Scientist Kevin Arrigo’s group from Stanford University.

Back in the ship's onboard lab, Frey and Arrigo's groups looked at the life contained in the samples, while Sam Laney of Woods Hole Oceanographic Institution fed them under an microscope that automatically collects images of the tiny life forms.

Researchers are finding strong connections between the properties of the ice and the communities of microbes beneath them. For example, ponds were found to transmit between three and 10 times more light than bare ice.

"Algae are affected by what's above them," said Laney, who noted that algae communities photographed under melt pond ice were different compared to those that turned up under white ice.

For more information visit http://www.nasa.gov/topics/earth/features/icescape2010_arctic_ice.html

Robot Goes to Work While Crew Prepares for Spacewalks

Robotics and spacewalk preparations took center stage Tuesday aboard the International Space Station as the Expedition 24 crew orbited above the Earth.

Dextre, an agile, two-armed extension for the station’s Canadarm2 robotic arm, continues its debut task to replace a failed Remote Power Control Module (RPCM) from a truss segment on the station’s port side. On Tuesday flight controllers in Houston began conducting a “dress rehearsal” of the actual replacement as they commanded Dextre to partially remove and reinstall an RPCM on the P1 truss. After Dextre successfully completes the test, Mission Control plans to swap the failed RPCM with a spare from the P3 truss Wednesday.

Meanwhile the Expedition 24 crew continued its own preparations to venture outside the station for an upcoming pair of spacewalks.

Image above: The Soyuz TMA-19 spacecraft (partially out of frame in the foreground), docked to the Rassvet Mini-Research Module 1, and the ISS Progress 37 resupply vehicle, docked to the Pirs Docking Compartment, are featured in this image. Credit: NASA

Cosmonauts Fyodor Yurchikhin and Mikhail Kornienko, both flight engineers, prepared the cooling loops of the Russian Orlan spacesuits they will wear during a six-hour spacewalk set to begin the evening of July 26. The pair will install Kurs automated rendezvous equipment on the exterior of the recently delivered Rassvet module to facilitate future dockings with Russian spacecraft.

Flight Engineers Doug Wheelock and Tracy Caldwell Dyson continued preparations for their Aug. 5 spacewalk as they each conducted a session of onboard training for Simplified Aid for EVA Rescue, or SAFER. Should a spacewalker become untethered during a spacewalk and begin floating away, the small nitrogen-jet thrusters of SAFER could help the astronaut get back to the station.

Shannon Walker, also a station flight engineer, assisted with the American spacewalk preparations as she inspected safety and waist tethers for structural integrity and reviewed spacewalk procedures.

The Expedition 24 crew also tackled a number of science investigations Tuesday. Commander Alexander Skvortsov spent part of his day working with a Russian experiment known as Russalka, which involves using a camera equipped with an ultraviolet filter to collect measurements of methane and carbon dioxide in the Earth’s atmosphere.

Wheelock prepared the Solution Crystallization Observation Facility for a Japanese study of facet-like crystallization. The results of this experiment may provide valuable data on creating high quality materials for industrial use such as superconducting magnets.

The Americans also continued maintenance work on the Oxygen Generation System, flushing the components that allow liquid to flow through the system so that oxygen can be extracted from recycled water to provide air for the crew to breathe.

Later, Walker assisted Wheelock with the latest session of Kids In Micro-Gravity!, an experiment that gives students a hands-on opportunity to design a demonstration that can be performed both in the classroom and aboard the station. Tuesday’s activity, a look at whether blowing across the tops of bottles filled with different amounts of water will create the same tones in space as on Earth, was developed by fifth grade students at Vaughan Elementary in Powder Springs, Ga.

Researchers can learn more about opportunities to develop and fly science experiments on the International Space Station (ISS) at the NASA ISS Research Academy Aug. 3-5 in League City, Texas.

For more information visit http://www.nasa.gov/mission_pages/station/main/index.html

NASA Finds Super-Hot Planet with Unique Comet-Like Tail

Astronomers using NASA's Hubble Space Telescope have confirmed the existence of a baked object that could be called a "cometary planet." The gas giant planet, named HD 209458b, is orbiting so close to its star that its heated atmosphere is escaping into space.

Observations taken with Hubble's Cosmic Origins Spectrograph (COS) suggest powerful stellar winds are sweeping the cast-off atmospheric material behind the scorched planet and shaping it into a comet-like tail.

"Since 2003 scientists have theorized the lost mass is being pushed back into a tail, and they have even calculated what it looks like," said astronomer Jeffrey Linsky of the University of Colorado in Boulder, leader of the COS study. "We think we have the best observational evidence to support that theory. We have measured gas coming off the planet at specific speeds, some coming toward Earth. The most likely interpretation is that we have measured the velocity of material in a tail."

The planet, located 153 light-years from Earth, weighs slightly less than Jupiter but orbits 100 times closer to its star than the Jovian giant. The roasted planet zips around its star in a short 3.5 days. In contrast, our solar system's fastest planet, Mercury, orbits the Sun in 88 days. The extrasolar planet is one of the most intensely scrutinized, because it is the first of the few known alien worlds that can be seen passing in front of, or transiting, its star. Linsky and his team used COS to analyze the planet's atmosphere during transiting events. During a transit, astronomers study the structure and chemical makeup of a planet's atmosphere by sampling the starlight that passes through it. The dip in starlight because of the planet's passage, excluding the atmosphere, is very small, only about 1.5 percent. When the atmosphere is added, the dip jumps to 8 percent, indicating a bloated atmosphere.

Illustration Credit: NASA, ESA, and G. Bacon (STScI)

COS detected the heavy elements carbon and silicon in the planet's super-hot, 2,000-degree-Fahrenheit atmosphere. This detection revealed the parent star is heating the entire atmosphere, dredging up the heavier elements and allowing them to escape the planet.

The COS data also showed the material leaving the planet was not all traveling at the same speed. "We found gas escaping at high velocities, with a large amount of this gas flowing toward us at 22,000 miles per hour," Linsky said. "This large gas flow is likely gas swept up by the stellar wind to form the comet-like tail trailing the planet."

Hubble's newest spectrograph has the ability to probe a planet's chemistry at ultraviolet wavelengths not accessible to ground-based telescopes. COS is proving to be an important instrument for probing the atmospheres of "hot Jupiters" like HD 209458b.

Another Hubble instrument, the Space Telescope Imaging Spectrograph (STIS), observed the planet in 2003. The STIS data showed an active, evaporating atmosphere, and a comet-tail-like structure was suggested as a possibility. But STIS wasn't able to obtain the spectroscopic detail necessary to show a tail, or an Earthward-moving component of the gas, during transits. The tail was detected for the first time because of the unique combination of very high ultraviolet sensitivity and good spectral resolution provided by COS.

Although this extreme planet is being roasted by its star, it won't be destroyed anytime soon. "It will take about a trillion years for the planet to evaporate," Linsky said.

The results appeared in the July 10 issue of The Astrophysical Journal.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI) conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc. in Washington, D.C.

For more information visit http://www.nasa.gov/mission_pages/hubble/science/planet-tail.html

Saturn System Moves Oxygen From Enceladus to Titan

Complex interactions between Saturn and its satellites have led scientists using NASA's Cassini spacecraft to a comprehensive model that could explain how oxygen may end up on the surface of Saturn's icy moon Titan. The presence of these oxygen atoms could potentially provide the basis for pre-biological chemistry.

The interactions are captured in two papers, one led by John Cooper and another led by Edward Sittler, published in the journal Planetary and Space Science in late 2009. Cooper and Sittler are Cassini plasma spectrometer team scientists at NASA's Goddard Space Flight Center in Greenbelt, Md.

"Titan and Enceladus, another icy moon of Saturn, are chemically connected by the flow of material through the Saturn system," Cooper said.

In one paper, Cooper and colleagues provide an explanation for forces that could generate the Enceladus geysers that spew water vapor into space. In the other, published in the same issue, Sittler and colleagues describe a unique new process in which oxygen that circulates in the upper atmosphere of Titan can be carried all the way to the surface without further chemical contamination by being encased in carbon cages called fullerenes.

The work draws upon previous work by Sittler and others that model the dynamics of how particles, including water molecules, travel from Enceladus to Titan. At Enceladus the flow process begins with what they call the "Old Faithful" model, after the Old Faithful geyser in Yellowstone National Park. In this model, gas pressure slowly builds up inside Enceladus, then gets released occasionally in geyser-like eruptions.

Unlike terrestrial geysers, or even geyser-like forces on Jupiter's moon Io, the model proposed by Cooper shows that charged particle radiation raining down from Saturn’s magnetosphere can create the forces from below the surface that are required to eject gaseous jets.

Energetic particles raining down from Saturn's magnetosphere – at Enceladus, mostly electrons from Saturn's radiation belts -- can break up molecules within the surface. This process is called radiolysis. Like a process called photolysis, in which sunlight can break apart molecules in the atmosphere, energetic radiation from charged particles that hit an icy surface, like that of Enceladus, can cause damage to molecules within the ice. These damaged molecules can get buried deeper and deeper under the surface by the perpetual churning forces that can repave the icy surface. Meteorites constantly crashing into the surface and splashing out material might also be burying the molecules.

This annotated image collage features Saturn and the moons Titan, Enceladus, Dione, Rhea and Helene, which are being studied by the Cassini mission. Image credit: NASA/JPL/Space Science Institute

When chemically altered icy grains come into contact beneath the surface with icy contaminants such as ammonia, methane and other hydrocarbons, they can produce volatile gases that can explode outward. Such gases can create plumes of the size seen by Cassini. Cooper and colleagues call such icy volatile mechanics "cryovolcanism."

What's unique about the "Old Faithful" model is that it "is a model for cryovolcanism that is based on not only liquid water, but also requires the production of gases by the radiolytic chemistry observed at Enceladus," said Sittler.

The plumes that emanate from Enceladus' south polar region consist of water, ammonia and other compounds. Scientists have known since the 1980s that Saturn's magnetosphere is inexplicably filled with neutral particles. In the intervening decades, particularly since the discovery of plumes jetting out from the south pole of Enceladus, work has shown how some of the water molecules that escape from Enceladus get split up into neutral and charged particles and are transported throughout Saturn's magnetosphere.

Sittler's new model indicates that as these broken water molecules enter Titan's atmosphere, they may be captured by fullerenes—hollow, soccer-ball shaped shells made of carbon atoms. Although the heavy molecules Cassini has detected in the upper atmosphere of Titan may be other molecules, Sittler suggests they are likely fullerenes.

In Sittler's model, the fullerenes then condense into larger clusters that can attach to polycyclic aromatic hydrocarbons—chemical compounds also found on Earth in oil, coal and tar deposits, and as the byproducts of burning fossil fuels. The fullerene clusters form even larger aerosols that travel down to Titan's surface.

This process protects the trapped oxygen from Titan's atmosphere, which is saturated with hydrogen atoms and compounds that are capable of breaking down other molecules. Otherwise, the oxygen would combine with methane in Titan's atmosphere and form carbon monoxide or carbon dioxide. Until now, scientists have not been able to explain how oxygen fits into the picture of the dynamics and chemistry of Saturn and its moons.

As the oxygen-rich aerosols fall to Titan's surface, they are further bombarded by products of galactic cosmic ray interactions with Titan's atmosphere. Cosmic rays bombarding the oxygen-stuffed fullerenes could produce more complex organic materials, such as amino acids, in the carbon-rich and oxygen-loaded fullerenes. Amino acids are considered important for pre-biological chemistry.

Scientists have been able to couple the new models that describe the generation of plumes at Enceladus and oxygen ion capture in fullerenes near the top of Titan's atmosphere to existing theories of the transport of oxygen across the magnetosphere. Taken together, Sittler and Cooper suggest a chemical pathway that allows the oxygen to be introduced to Titan's surface chemistry.

"Cooper and Sittler's work helps us understand more about the potential for chemical interactions among Saturn's moons," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"The Saturn system is indeed a dynamic place, with the Enceladus plumes creating the E ring and loading the magnetosphere with water which interacts with Titan and the other moons," Spilker said.

The Cassini mission is a joint effort of NASA, the European Space Agency, and the Italian space agency Agenzia Spaziale Italiana. The mission is managed for NASA by the Jet Propulsion Laboratory, a division of the California Institute of Technology. Partners include the U.S. Air Force, Department of Energy, and academic and industrial participants from 19 countries.

For more information visit http://www.nasa.gov/mission_pages/cassini/whycassini/saturn20100701.html

Tile Testing

In Orbiter Processing Facility-3 at NASA’s Kennedy Space Center in Florida, United Space Alliance tile technician Jimmy Carter works on boundary layer transition tile bonding on space shuttle Discovery's leading wing edge.

The boundary layer transition tiles are part of testing designed to help engineers better understand the heating environment around a spacecraft as it reenters the atmosphere.

Discovery and its crew for the STS-133 mission are targeted to deliver the Express Logistics Carrier-4 filled with external payloads and experiments, as well as critical spare components to the International Space Station.

Image credit: NASA/Frankie Martin
June 25, 2010

For more information visit http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/multimedia/gallery/10-06-25.html

Next Mars Rover Sports a Set of New Wheels

PASADENA, Calif. – NASA's next Mars rover, Curiosity, is sitting pretty on a set of spiffy new wheels that would be the envy of any car show on Earth.

The wheels and a suspension system were added this week by spacecraft technicians and engineers. These new and important touches are a key step in assembling and testing the flight system in advance of a planned 2011 launch.

Mars rover Curiosity, the centerpiece of NASA's Mars Science Laboratory mission, is coming together for extensive testing prior to its late 2011 launch. Image Credit: NASA/JPL-Caltech

Curiosity, centerpiece of NASA's Mars Science Laboratory mission, is a six-wheeler and uses a rocker-bogie suspension system like its smaller predecessors: Spirit, Opportunity and Sojourner. Each wheel has its own drive motor, and the corner wheels also have independent steering motors. Unlike earlier Mars rovers, Curiosity will also use its mobility system as a landing gear when the mission's rocket-powered descent stage lowers the rover directly onto the Martian surface on a tether in August 2012.

In coming months at NASA's Jet Propulsion Laboratory, the mobility system will get functional testing and be part of environmental testing of the rover. The mobility system will now stay on Curiosity through launch unless testing identifies a need for rework that would require it to be disassembled.

With the wheels and suspension system already installed onto one side of NASA's Mars rover Curiosity the previous day, spacecraft engineers and technicians prepare the other side's mobility subsystem for installation on June 29, 2010. Image Credit: NASA/JPL-Caltech

The mission will launch from Florida during the period Nov. 25 to Dec. 18, 2011. Curiosity will examine an area of Mars for modern or ancient habitable environments, including any that may have also been favorable for preserving clues about life and environment, though this mission will not seek evidence of life. It will examine rocks, soil and atmosphere with a diverse payload of tools, including a laser to vaporize patches of rock from a distance and an instrument designed to test for organic compounds.

For more information visit http://www.nasa.gov/mission_pages/msl/msl20100701.html

NASA Awards Launch Services Contract for OCO-2 Mission

PASADENA, Calif. – NASA has selected Orbital Sciences Corp. of Dulles, Va., to launch the Orbiting Carbon Observatory-2 (OCO-2) mission. The spacecraft will fly in February 2013 aboard a Taurus XL 3110 rocket launched from Vandenberg Air Force Base in California.

The total cost of the OCO-2 launch services is approximately $70 million. The estimated cost includes the task ordered launch service for a Taurus XL 3110 rocket, plus additional services under other contracts for payload processing, OCO-2 mission-unique support, launch vehicle integration, and tracking, data and telemetry support.

This is an artist’s concept of the Orbiting Carbon Observatory. Image credit: NASA/JPL

OCO-2 is NASA's first mission dedicated to studying atmospheric carbon dioxide. Carbon dioxide is the leading human-produced greenhouse gas driving changes in Earth's climate. OCO-2 will provide the first complete picture of human and natural carbon dioxide sources and "sinks," the places where the gas is pulled out of the atmosphere and stored. It will map the global geographic distribution of these sources and sinks and study their changes over time. The OCO-2 spacecraft will replace OCO-1, lost during a launch vehicle failure in 2009.

The OCO-2 project is managed by the Jet Propulsion Laboratory in Pasadena, Calif. NASA's Launch Services Program at the Kennedy Space Center in Florida is responsible for launch vehicle program management of the Taurus XL 3110 rocket.

For more information about NASA and agency missions, visit: http://www.nasa.gov . For more on OCO-2, visit: http://oco.jpl.nasa.gov/ .

JPL is managed for NASA by the California Institute of Technology in Pasadena.

For more information visit http://www.nasa.gov/mission_pages/oco/news/oco20100622.html

Crew Does Maintenance, Science; Soyuz Launch Date Approaches

The International Space Station’s Expedition 24 crew began the week Monday with a variety of science experiments.

Flight Engineer Tracy Caldwell Dyson was scheduled to reinstall an old pump into the U.S. segment’s oxygen generation system, in an effort to coax it back into action to support the increase of the crew to six people which will begin Thursday.

Flight Engineer Mikhail Kornienko restarted the Elektron oxygen generation system in the Russian segment over the weekend.

Commander Alexander Skvortsov conducted an observation with the Rusalka experiment, which is a test of procedures for remote determination of methane and carbon dioxide content in the Earth’s atmosphere.

Skvortsov also assisted Kornienko in a session with the Russian Pilot-M experiment. Pilot-M tests piloting skill in simulations on a laptop under stopwatch control and studies the response of cosmonauts to the effects of stress factors in flight.

Image above: The Soyuz TMA-19 spacecraft is rolled out by train to the launch pad at the Baikonur Cosmodrome, Kazakhstan, Sunday, June 13, 2010. Credit: NASA/Carla Cioffi

Caldwell Dyson took photographs of the moon for the Japan Aerospace Exploration Agency educational program known as ISS Moon Score. The purpose of this program is to create a musical score using photos of the moon taken at different times in the lunar cycle, while the crew is floating naturally in the microgravity environment.

Following the rollout of their Soyuz TMA-19 spacecraft to the launch pad Sunday, Expedition 24 Flight Engineers Doug Wheelock, Shannon Walker and Fyodor Yurchikhin met Monday with the Russian State Commission of top space officials and conducted their final pre-launch Crew News Conference at their Cosmonaut Hotel crew quarters. Everything is on track for launch Tuesday at 5:35 p.m. EDT. The new crew members are slated to dock to the station’s Zvezda service module Thursday at 6:25 p.m.

For more information visit http://www.nasa.gov/mission_pages/station/main/index.html

NASA Rover Finds Clue to Mars' Past And Environment for Life

PASADENA, Calif. -- Rocks examined by NASA's Spirit Mars Rover hold evidence of a wet, non-acidic ancient environment that may have been favorable for life. Confirming this mineral clue took four years of analysis by several scientists.

An outcrop that Spirit examined in late 2005 revealed high concentrations of carbonate, which originates in wet, near-neutral conditions, but dissolves in acid. The ancient water indicated by this find was not acidic.

NASA's rovers have found other evidence of formerly wet Martian environments. However the data for those environments indicate conditions that may have been acidic. In other cases, the conditions were definitely acidic, and therefore less favorable as habitats for life.

Lengthy detective work with data NASA's Mars Exploration Rover Spirit collected in late 2005 has confirmed that an outcrop called "Comanche" contains a mineral indicating that a past environment was wet and non-acidic, possibly favorable to life. Image credit: NASA/JPL-Caltech/Cornell University

Laboratory tests helped confirm the carbonate identification. The findings were published online Thursday, June 3 by the journal Science.

"This is one of the most significant findings by the rovers," said Steve Squyres of Cornell University in Ithaca, N.Y. Squyres is principal investigator for the Mars twin rovers, Spirit and Opportunity, and a co-author of the new report. "A substantial carbonate deposit in a Mars outcrop tells us that conditions that could have been quite favorable for life were present at one time in that place. "

Spirit inspected rock outcrops, including one scientists called Comanche, along the rover's route from the top of Husband Hill to the vicinity of the Home Plate plateau which Spirit has studied since 2006. Magnesium iron carbonate makes up about one-fourth of the measured volume in Comanche. That is a tenfold higher concentration than any previously identified for carbonate in a Martian rock.

"We used detective work combining results from three spectrometers to lock this down," said Dick Morris, lead author of the report and a member of a rover science team at NASA's Johnson Space Center in Houston."The instruments gave us multiple, interlocking ways of confirming the magnesium iron carbonate, with a good handle on how much there is."

Massive carbonate deposits on Mars have been sought for years without much success. Numerous channels apparently carved by flows of liquid water on ancient Mars suggest the planet was formerly warmer, thanks to greenhouse warming from a thicker atmosphere than exists now. The ancient, dense Martian atmosphere was probably rich in carbon dioxide, because that gas makes up nearly all the modern, very thin atmosphere.

It is important to determine where most of the carbon dioxide went. Some theorize it departed to space. Others hypothesize that it left the atmosphere by the mixing of carbon dioxide with water under conditions that led to forming carbonate minerals. That possibility, plus finding small amounts of carbonate in meteorites that originated from Mars, led to expectations in the 1990s that carbonate would be abundant on Mars. However, mineral-mapping spectrometers on orbiters since then have found evidence of localized carbonate deposits in only one area, plus small amounts distributed globally in Martian dust.

Morris suspected iron-bearing carbonate at Comanche years ago from inspection of the rock with Spirit's Moessbauer Spectrometer, which provides information about iron-containing minerals. Confirming evidence from other instruments emerged slowly. The instrument with the best capability for detecting carbonates, the Miniature Thermal Emission Spectrometer, had its mirror contaminated with dust earlier in 2005, during a wind event that also cleaned Spirit's solar panels.

NASA's Mars Rover Spirit began its Mars exploration at its landing site in January 2004. Image credit: NASA/JPL-Caltech/UA/Cornell/NM Museum of Natural History and Science

"It was like looking through dirty glasses," said Steve Ruff of Arizona State University in Tempe, Ariz., another co-author of the report. "We could tell there was something very different about Comanche compared with other outcrops we had seen, but we couldn't tell what it was until we developed a correction method to account for the dust on the mirror."

Spirit's Alpha Particle X-ray Spectrometer instrument detected a high concentration of light elements, a group including carbon and oxygen, that helped quantify the carbonate content.

The rovers landed on Mars in January 2004 for missions originally planned to last three months. Spirit has been out of communication since March 22 and is in a low-power hibernation status during Martian winter. Opportunity is making steady progress toward a large crater, Endeavour, which is about seven miles away.

NASA's Jet Propulsion Laboratory, Pasadena, manages the Mars Exploration Rovers for the agency's Science Mission Directorate in Washington. For more information about the rovers, visit:

http://www.nasa.gov/rovers

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer20100603.html

NASA Center for Climate Simulation: Data Supporting Science

Debuting in spring 2010, the NASA Center for Climate Simulation (NCCS) is the new name for a Goddard Space Flight Center organization that has provided supercomputing resources to NASA scientists and engineers for over 25 years.

"Computation here at Goddard is primarily to create datasets and make them available for science researchers around the world," said Phil Webster, chief of Goddard's Computational and Information Sciences and Technology Office, which includes NCCS. With climate and weather modeling representing the bulk of NCCS computing, the new name reflects "our mission to support NASA Earth science."

Supercomputing the Climate

This short video introduces the NCCS and takes you behind-the-scenes into the fascinating field of climate modeling. Credit: NASA/Goddard Space Flight Center

› Download this video from Goddard's Scientific Visualization Studio

This science is carried out by hundreds of NCCS users from Goddard, other NASA centers, laboratories, and universities across the U.S. The two largest user groups are Goddard's Global Modeling and Assimilation Office (GMAO), headed by Michele Rienecker, and the Goddard Institute for Space Studies (GISS), directed by Jim Hansen. NCCS-hosted simulations span time scales from days (weather prediction) to seasons and years (short-term climate prediction) to decades and centuries (climate change projection).

Data-Centric Science

At any time scale, NASA climate simulations use and produce vast amounts of data. "The unique thing about NASA is that we are the source of most of the research satellite observational data of the atmosphere, land, and ocean," Webster said. Add data from the National Oceanic and Atmospheric Administration (NOAA) and other sources, and GMAO needs to process as many as 8 million observations from satellites and additional platforms per day before assimilating them into models.

The NASA Center for Climate Simulation (NCCS) Data Exploration Theater features a 17- by 6-foot multi-screen visualization wall for engaging visitors and scientists with high-definition movies of simulation results. Here, the wall displays a 3.5-kilometer-resolution global simulation that captures numerous cloud types at groundbreaking fidelity. Credit: NASA/Goddard/Pat Izzo

Data assimilation and other techniques create the right starting conditions for simulating physical processes around the Earth. In predicting future conditions, climate models generate data much like the observations: temperature, humidity, wind speed and direction, precipitation, and other values. Data processing requirements can be considerable. The largest project run at NCCS to date -- GMAO's Modern Era Retrospective-analysis for Research and Applications (MERRA) -- ingests more than 50 billion observations over the Earth Observing System satellite era. MERRA will eventually produce more than 150 terabytes (tera = trillion) of value-added Earth science data.

Today's climate science is "data-centric," as Webster describes it. "Everything we do supports the creation, utilization, and exploitation of Earth science model data," he said. The new NCCS is expanding its services to meet NASA's growing climate data needs.

Augmented Supercomputer

The heart of the new NCCS is the "Discover" supercomputer. In 2009, NCCS added more than 8,000 computer processors to Discover, for a total of nearly 15,000 processors. The new processors are from Intel's latest Xeon 5500 series, which uses the Nehalem architecture introduced in spring 2009. Nehalem is well suited to climate studies, offering greater speed, larger memory, and faster memory access than processors installed just one year before. Significant augmentations to Discover will occur in summer 2010.

"With the new augmentations of Discover we probably have a 3 to 4x increase in the amount of work that we can push through the computer in a day," Webster said. "You can run more simulations at the same resolutions you've had, but the thing that really excites us is that we can run much higher resolution simulations."

The heart of NCCS is the “Discover” supercomputer. In 2009, NCCS added more than 8,000 computer processors to Discover, for a total of nearly 15,000 processors. Discover-hosted simulations span time scales from days (weather prediction) to seasons and years (short-term climate prediction) to decades and centuries (climate change projection). Credit: NASA/Pat Izzo

Using Discover's new Nehalem processors, a "cubed-sphere" version of GMAO's flagship Goddard Earth Observing System Model, Version 5 (GEOS-5) ran at resolutions including 3.5 kilometers -- equaling the highest resolution to date for a global climate model. Most startling is the formation of numerous cloud types at groundbreaking fidelity. "When you hold that up against pictures taken from satellites, it's almost impossible to tell the difference between the simulation and the pictures," Webster said.

Working with Data

In addition to powerful computers, NCCS has long had a massive data archive for researchers to store, and later retrieve, model output and other data. The archive's current capacity is 17.5 petabytes (peta = 1,000 trillion). A new data management system (DMS) will reduce dataset duplication and keep the most heavily used datasets online for faster access. DMS software tools will help users to more easily locate and access the data they need.

NCCS is also expanding its data analysis and visualization capabilities. Webster explained that it is very difficult to analyze terabytes of data on a standard workstation, which might have a few hundred gigabytes of disk and perhaps eight gigabytes of memory. The NCCS' "Dali" analysis system offers "a machine comparable to the size of the data that is being generated by the computing center," Webster said. It is "specifically designed to allow a scientist to use that data as quickly as possible." Dali's capabilities include data visualization, scientific workflow management, and diagnostics for model evaluation and comparison. For visualization at room size, a 17- by 6-foot multi-screen visualization wall is engaging visitors and scientists with high-definition movies of simulation results.

Over the last few years, NCCS has distributed simulation data to users and non-users alike through its Data Portal. Especially to support data distribution for NASA's Intergovernmental Panel on Climate Change (IPCC) simulations, NCCS is deploying a node on the Earth System Grid (ESG). ESG integrates supercomputers with large-scale data and analysis servers at national laboratories and research centers, with the goal of "turning climate datasets into community resources."

The Modern Era Retrospective-analysis for Research and Applications (MERRA) is producing a comprehensive record of Earth’s weather and climate from 1979, the beginning of the operational Earth observing satellite era, up to the present. This visualization depicts specific atmospheric humidity on June 17, 1993, during the Great Flood that hit the Midwestern United States. Credit: Research: Michele Rienecker, Max Suarez, Ron Gelaro, Julio Bacmeister, Ricardo Todling, Larry Takacs, Emily Liu, Steve Pawson, Mike Bosilovich, Siegfried Schubert, Gi-Kong Kim, NASA/Goddard; Visualization: Trent Schindler, NASA/Goddard/UMBC

The IPCC's Fifth Assessment Report, due to be completed in 2014, will include input from climate modeling groups worldwide. NASA contributions will come from GISS and GMAO, which are running the latest versions of their models on Discover. GISS ModelE will perform simulations going back a full millennium and forward to 2100. GMAO will focus on the years 1960 to 2035 and perform decadal prediction simulations using GEOS-5 and atmospheric chemistry-climate simulations using the GEOS Chemistry Climate Model. Employing ESG and its common data format, NCCS expects to distribute more than 50 terabytes of data from IPCC simulations to the climate research community.

Within that community, Webster sees Goddard and NCCS as particularly equipped to make contributions. "We have a tremendous amount of observational data, which is captured by our satellites," he said. "We have probably the largest collection of Earth scientists anywhere in the world, and we have this new state-of-the-art computing center. The combination of the data, the scientists, and the computing puts us in a unique position to enable advances in weather and climate research."

Related Links

NASA Center for Climate Simulation – http://www.nccs.nasa.gov/

Global Modeling and Assimilation Office – http://gmao.gsfc.nasa.gov/

Goddard Institute for Space Studies – http://www.giss.nasa.gov/

NASA High-End Computing Program – http://www.hec.nasa.gov/

Multimedia Resources – http://svs.gsfc.nasa.gov/Gallery/NCCS.html

For more information visit http://www.nasa.gov/topics/earth/features/climate-sim-center.html