Brown Dwarf Comparison

NASA's Wide-field Infrared Survey Explorer, or WISE, will uncover many "failed" stars, or brown dwarfs, in infrared light. This diagram shows a brown dwarf in relation to Earth, Jupiter, a low-mass star and the sun.

Stars with less mass than the sun are smaller and cooler, and hence much fainter in visible light. Brown dwarfs are the smallest and coolest of stars. They have less than eight percent of the mass of the sun, which is not enough to sustain the fusion reaction that keeps the sun hot. These cool orbs are nearly impossible to see in visible light, but stand out when viewed in infrared. Their diameters are about the same as Jupiter's, but they can have up to 80 times more mass and are thought to have planetary systems of their own.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Wide-field Infrared Survey Explorer for NASA's Science Mission Directorate, Washington. The mission's principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

More information is online at http://www.nasa.gov/wise and http://wise.astro.ucla.edu.

Image Credit: NASA/JPL-Caltech/UCB

For more information visit http://www.nasa.gov/mission_pages/WISE/multimedia/pia12462.html

Mission STS-129: Delivering the Goods

Space shuttle Atlantis' STS-129 mission was an ambitious and demanding undertaking that began Nov. 16, 2009, with a spectacular and on-time liftoff at 2:28 p.m. EST from NASA's Kennedy Space Center in Florida.

Aboard were Commander Charles O. Hobaugh, Pilot Barry E. Wilmore, Mission Specialists Leland Melvin, Mike Foreman, Robert L. Satcher Jr. and Randy Bresnik. In addition to the crew, there were nearly 30,000 pounds of replacement parts packed in the Express Logistics Carriers, or ELCs, secured inside Atlantis' payload bay.

With a picture-perfect launch behind them, the first task at hand on Nov. 17 was checking the shuttle's wing leading edges and nose cap using the orbiter boom sensor system. The end of the boom consists of cameras and lasers, giving experts on the ground 3-D views of the shuttle's heat shield to ensure there wasn't any damage from launch.

Image above: Space shuttle Atlantis lifts off from the exhaust cloud building on Launch Pad 39A at NASA's Kennedy Space Center in Florida. Photo credit: NASA/Sandra Joseph and Kevin O'Connell

Later in the day while the shuttle was catching up with the International Space Station, Bresnik, Foreman and Satcher checked out the two spacesuits they would use for the three planned spacewalks.

Once in range of the station on Nov. 18, the shuttle was delicately maneuvered into the rendezvous pitch maneuver, or "backflip," where Expedition 21 Flight Engineers Jeffrey Williams and Nicole Stott took photos from their vantage point.

Images from the first and second inspection were sent back to Earth for experts to review, making sure the shuttle would have a safe flight back through Earth's atmosphere.

Hobaugh then carefully guided Atlantis closer to the station until it was locked into the station's docking port on the Harmony node. It took a couple hours for a series of hatch leak checks to be performed and once accomplished, the hatches were opened and the Atlantis crew was enthusiastically greeted and welcomed aboard the station by the Expedition 21 team.

Image above: Backdropped by Earth's horizon, a partial view of Atlantis' payload bay, vertical stabilizer, orbital maneuvering system pods and docking mechanism are featured in this image. Photo credit: NASA/JSC

As the hatch opened, Nicole Stott's responsibilities as station flight engineer officially ended and she became an STS-129 mission specialist for the remainder of her time in space. Stott is the last NASA astronaut to experience the rotation of launching from and being returned to Earth by a space shuttle. In the future, a Russian Soyuz spacecraft will be used for station crew rotations.

With a demanding to-do list ahead of them, the two crews began with the first task at hand. ELC 1 was grappled from Atlantis' payload bay by Melvin and Bresnik with the shuttle's robotic arm and handed off to the station's robotic arm controlled by Wilmore and Williams. The platform was permanently installed to the outside of the station to store large cargo.

That evening Foreman and Satcher spent the night camping out in the Quest airlock preparing for their first spacewalk. After stepping out into space the next day, Foreman and Satcher completed all major tasks almost two hours ahead of schedule. In addition, Foreman was able to successfully connect a cable on the Unity node -- one that was uncooperative for the STS-128 crew in September.

Image above: STS-129 and Expedition 21 crew members greet each other shortly after space shuttle Atlantis and the International Space Station docked in space and the hatches were opened. Photo credit: NASA/JSC

Inside the station, work was ongoing to prepare for the arrival of the Tranquility node, which will be flown on shuttle Endeavour's STS-130 mission targeted for early 2010.

Overnight, a false depressurization alarm sounded and woke the crew, but flight control teams on the ground determined there was no danger to the station or crew. In the STS-129 post-landing crew press conference, said, "The training the crew members received helped them deal with the false alarms that went off a few times during their stay on the orbiting outpost."

The relocation of supplies and equipment between Atlantis and the station continued Nov. 20, in addition to tackling a variety of maintenance, troubleshooting and science activities -- keeping both station and shuttle crews busy.

Early the next morning, the second carrier with almost 10,000 pounds of large spare parts, including an attitude-control gyroscope, was moved from the shuttle's cargo bay to its permanent location on the S3 side of the station's truss, or backbone.

Image above: Mission Specialist Randy Bresnik, near the Columbus laboratory, participates in the STS-129 mission's second spacewalk. Photo credit: NASA/JSC

The two platforms that were attached to the station allow additional storage space for the mountain of supplies and equipment needed for the smooth and efficient running of the orbiting laboratory, now and well into the future after the shuttles are retired.

A little later, Foreman and Bresnik made their way into the emptiness of space for the second successful spacewalk of the mission. They not only completed their tasks ahead of schedule but also accomplished some get-ahead jobs -- all in six hours, eight minutes.

Meanwhile, another success story was in the making. On the morning of Nov. 22, Bresnik was told by the Mission Control Center in Houston that his wife, Rebecca, had given birth to their daughter, Abigail Mae Bresnik. He was assured that both baby and mother were doing just fine. Atlantis' crew members were given a well-earned, half day off to celebrate. The rest of day was dedicated to preparing for the third spacewalk on Nov. 23, featuring Satcher and Bresnik.

Image above: STS-129 and Expedition 21 crew members gather for a formal portrait. Photo credit: NASA/JSC

The space excursion began more than an hour later than planned because a drinking-water valve in Satcher's spacesuit became dislodged and the helmet had to be opened to reattach the valve. With the fix behind them, Bresnik and Satcher completed all the tasks in just five hours, 42 minutes -- almost on time, regardless of the late start.

Later, the last of the mission's spare hardware was moved thanks to the combined effort of all 12 shuttle and station crew members.

On Nov. 22, the shuttle and station crew members said their final farewells before the hatches between shuttle Atlantis and the station were securely closed -- after which the shuttle crew prepared for undocking.

Wilmore eased the shuttle away from the station circling around the outpost. Crew members videoed and snapped photos of the orbiting laboratory in order to assess its exterior condition.

One more survey was in store for the shuttle's heat shield with Wilmore and Melvin using the orbiter boom sensor system -- a five-hour process.

Image above: Space shuttle Atlantis touches down on the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. Photo credit: NASA/Tim Terry

Atlantis crew members spent part of Thanksgiving preparing for their Nov. 27 landing date. They tested the thruster jets that control the shuttle's orientation in space and during early re-entry, as well as the flaps and rudders that guide it through the atmosphere.

The day didn't pass without a surprise, though. A traditional turkey dinner with all the trimmings found its way aboard Atlantis before undocking -- compliments of the Expedition 21 crew members.

It was a perfect end to a nearly perfect mission. After the twin sonic booms echoed and Atlantis came out of a clear-blue sky, the vehicle and crew touched down on Kennedy's Shuttle Landing Facility on Nov. 27 at 9:44 a.m. EST.

After winding up a successful 11-day flight to deliver spare parts, other equipment and supplies to the International Space Station, the crew took their last walk around the vehicle that served them well from start to finish.

After a short ride to crew quarters, the astronauts were given a thorough medical exam and met with their families. On Nov. 28, the crew flew home to Houston, and on Nov. 30, they were honored at a homecoming ceremony held at nearby Ellington Field.

Atlantis' STS-129 mission was the 31st flight dedicated to space station assembly, resupply and maintenance -- one that should help keep the station supplied well into the future.

Elaine M. Marconi
NASA's John F. Kennedy Space Center

For more information visit http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts129/launch/129_overview.html

Off-Duty Day for Station Crew

Expedition 22 Commander Jeff Williams and Flight Engineer Max Suraev of the two-person International Space Station crew enjoyed their second of two off-duty days Wednesday.

Three more crew members, Russian cosmonaut Oleg Kotov, Japan Aerospace Exploration Agency astronaut Soichi Noguchi and NASA astronaut T.J. Creamer, all flight engineers, are scheduled to launch on the Soyuz TMA-17 Dec. 20 and will arrive at the station Dec. 23.

Meanwhile, Expedition 21 crew members Frank De Winne, Roman Romanenko and Bob Thirsk arrived in Star City, Russia about 10 a.m. EST (about 6 p.m. Moscow time) Wednesday and were reunited with their families.

De Winne, Romanenko and Thirsk returned to Earth aboard the Soyuz TMA-15 spacecraft at 2:15 a.m. Tuesday, landing on the steppes of Kazakhstan.

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

Erg Iabes, Algeria

Vast, windswept plains of sand dunes (ergs), occasionally interrupted by rocky outcrops, stretch across much of Algeria in a giant C-shape. Except for exceedingly rare oases, these seas of sand are usually empty of life, including human civilization.

This natural-color image from the Landsat 5 satellite shows the emptiness of the Erg Iabès in western Algeria’s Adrar province. This rather small erg (compared to the country’s Grand Ergs) occupies the wide gap between the El Eglab Massif to the west and the Tademaït Plateau to the northeast.

Long, linear dunes such as the ones pictured here align in the direction of the prevailing winds, and they usually form under the influence of strong winds. However, linear dunes are not the only types of dunes that are found in ergs. For example, weaker winds blowing over a linear dune in the non-prevailing wind direction may create star dunes. Barchan dunes are shaped like a crescent, with a more gradual slope on the windward side, and a steeper slope on the downwind side.

For more information visit http://earthobservatory.nasa.gov/IOTD/view.php?id=41476

Suzaku Spies Treasure Trove of Intergalactic Metal

Every cook knows the ingredients for making bread: flour, water, yeast, and time. But what chemical elements are in the recipe of our universe?

Most of the ingredients are hydrogen and helium. These cosmic lightweights fill the first two spots on the famous periodic table of the elements.

Less abundant but more familiar to us are the heavier elements, meaning everything listed on the periodic table after hydrogen and helium. These building blocks, such as iron and other metals, can be found in many of the objects in our daily lives, from teddy bears to teapots.

The Perseus galaxy cluster contains 190 galaxies and lies about 225 million light-years away. Credit: Robert Lupton and the Sloan Digital Sky Survey Consortium

Recently astronomers used the Suzaku orbiting X-ray observatory, operated jointly by NASA and the Japanese space agency, to discover the largest known reservoir of rare metals in the universe.

Suzaku detected the elements chromium and manganese while observing the central region of the Perseus galaxy cluster. The metallic atoms are part of the hot gas, or "intergalactic medium," that lies between galaxies.

"This is the first detection of chromium and manganese from a cluster," says Takayuki Tamura, an astrophysicist at the Japan Aerospace Exploration Agency who led the Perseus study. "Previously, these metals were detected only from stars in the Milky Way or from other galaxies. This is the first detection in intergalactic space."

The cluster gas is extremely hot, so it emits X-ray energy. Suzaku's instruments split the X-ray energy into its component wavelengths, or spectrum. The spectrum is a chemical fingerprint of the types and amounts of different elements in the gas.

This Hubble Space Telescope image shows NGC 1275, a galaxy located in the center of the Perseus cluster. The red threadlike filaments are composed of cool gas suspended by a magnetic field. Credit: NASA/ESA/Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration

The portion of the cluster within Suzaku's field of view is some 1.4 million light-years across, or roughly one-fifth of the cluster's total width. It contains a staggering amount of metal atoms. The chromium is 30 million times the sun's mass, or 10 trillion times Earth's mass. The manganese reservoir weighs in at about 8 million solar masses.

Exploding stars, or supernovas, forge the heavy elements. The supernovas also create vast outflows, called superwinds. These galactic gusts transport heavy elements into the intergalactic void.

Harvesting the riches of the Perseus Cluster is not possible. But researchers will mine the Suzaku X-ray data for scientific insights.

"By measuring metal abundances, we can understand the chemical history of stars in galaxies, such as the numbers and types of stars that formed and exploded in the past," Tamura says.

The Suzaku study data show it took some 3 billion supernovas to produce the measured amounts of chromium and manganese. And over periods up to billions of years, superwinds carried the metals out of the cluster galaxies and deposited them in intergalactic space.

This image from the Japanese Advanced Satellite for Cosmology and Astrophysics shows the X-ray glow of the 100-million-degree Fahrenheit gas that fills the Perseus cluster. The white box indicates the area explored by the Suzaku X-ray telescope to detect chromium and manganese. The image is about two degrees wide, or four times the apparent width of a full moon. Credit: JAXA

A complete history of the universe should include an understanding of how, when, and where the heavy elements formed -- the chemical elements essential to life itself. The Suzaku study contributes to a larger ongoing effort to take a chemical census of the cosmos. "It's a part of learning the entire history of chemical element formation in the universe," notes Koji Mukai, who heads the Suzaku Guest Observer program at NASA's Goddard Space Flight Center in Greenbelt, Md.

With more than 10,000 galaxy clusters known, astronomers have just barely begun their work. "The current Suzaku result cannot answer these big questions immediately," Tamura says, "but it is one of the first steps to understand the chemical history of the universe."

The study appeared in the November 1 issue of The Astrophysical Journal Letters.

Related links:

Suzaku Snaps First Complete X-ray View of a Galaxy Cluster
http://www.nasa.gov/mission_pages/astro-e2/news/xray_cluster.html

Daniel Pendick
NASA's Goddard Space Flight Center

For more information visit http://www.nasa.gov/mission_pages/astro-e2/news/intergalactic_metal.html

Expedition 21 Crew Lands in Kazakhstan

Expedition 21 Flight Engineer and Soyuz Commander Roman Romanenko, European Space Agency Flight Engineer Frank De Winne and Canadian Space Agency Flight Engineer Robert Thirsk have returned to Earth, landing on the steppes of Kazakhstan in their Soyuz TMA-15 spacecraft. Landing occurred at 2:15 a.m. EST Tuesday, 1:15 p.m. Kazakhstan time.

All three crew members were reported to be in good condition. Due to icy conditions at the landing site, the landing support team recalled its helicopters to their bases in Kustanai and Arkalyk, Kazakhstan. Instead the team arrived in all-terrain vehicles from nearby Arkalyk to extract the Expedition 21 crew members from the Soyuz crew module.

Romanenko, De Winne and Thirsk spent 188 days in space, 186 of those aboard the orbiting International Space Station. The three arrived at the station in May as part of Expedition 20, which marked the start of six-person crew operations aboard the station. With their arrival, all five of the international partner agencies – NASA, the Russian Federal Space Agency (Roscosmos), the Japan Aerospace Exploration Agency (JAXA), the European Space Agency (ESA) and the Canadian Space Agency (CSA) – were represented on orbit for the first time.

Romanenko, a cosmonaut with Roscosmos, served as a flight engineer for Expeditions 20 and 21. He was selected as a test-cosmonaut candidate of the Gagarin Cosmonaut Training Center Cosmonaut Office in December 1997. The son of veteran Cosmonaut Yuri Romanenko, he qualified as a test cosmonaut in November 1999.

Image above: The Soyuz TMA-15 spacecraft carrying Flight Engineers Frank De Winne, Roman Romanenko and Robert Thirsk lands in the steppes of Kazakhstan. Credit: Roscosmos/NASA TV

De Winne, an ESA astronaut, served as a flight engineer for Expeditions 20 and 21 and commander for Expedition 21. He spent nine days aboard the station in 2002 as a member of the Odissea mission arriving on a new spacecraft, the Soyuz TMA-1, then leaving on an older Soyuz TM-34.

Thirsk, a CSA astronaut, served as a flight engineer for Expeditions 20 and 21. In 1996, Thirsk flew as a payload specialist astronaut aboard space shuttle mission STS-78, the Life and Microgravity Spacelab mission.

After traveling back to the Gagarin Cosmonaut Training Center in Star City, Russia, the crew members will be reunited with their families and start their reorientation to a gravity environment after a half year off the planet.

Commander Jeff Williams and Flight Engineer Maxim Suraev remain on the station, comprising the Expedition 22 crew as a two-man contingent for three weeks until the arrival Dec. 23 of Russian cosmonaut Oleg Kotov, NASA’s T.J. Creamer, and Soichi Noguchi of the Japan Aerospace Exploration Agency, who will launch to the station Dec. 20 on the Soyuz TMA-17 craft.

For more information visit http://www.nasa.gov/mission_pages/station/expeditions/expedition21/exp21_land.html

NASA Uses Twin Processes to Develop New Tank Dome Technology

NASA has partnered with Lockheed Martin Space Systems in Denver, Colo., and MT Aerospace in Augsburg, Germany, to successfully manufacture the first full-scale friction stir welded and spun formed tank dome designed for use in large liquid propellant tanks.

The NASA and Lockheed Martin team traveled to Germany to witness the first successful aerospace application of two separate manufacturing processes: friction stir welding, a solid-state joining process, and spin forming, a metal working process used to form symmetric parts.

The twin processes were used by MT Aerospace to produce an 18-foot-diameter tank dome using high-strength 2195 aluminum-lithium. The diameter of this development dome matches the tank dimensions of the upper stage of the ARES I launch vehicle under development by NASA, as well as the central stage of the European Ariane V launcher.

A full-scale spherical tank dome measuring 18 feet in diameter was produced from high-strength 2195 aluminum-lithium using twin manufacturing processes. Image credit: MT Aerospace

"This new manufacturing technology allows us to use a thinner, high-strength alloy that will reduce the weight of future liquid propellant tanks by 25 percent, compared to current tank designs that use a lower-strength aluminum alloy that weighs more," said Louis Lollar, project lead for the Friction Stir Weld Spun Form Dome Project at NASA's Marshall Space Flight Center in Huntsville, Ala.

The concave net shape spin forming process, patented by MT Aerospace, drastically simplifies the manufacturing of large tank domes and reduces cost by eliminating manufacturing steps, such as machining and assembly welding, that are required when manufacturing traditional gore panel - a pie-shaped section of the tank dome --construction domes.

"The success of this project is proof positive that when innovation, partnership and expertise are brought together, we can deliver new capabilities at lower cost with greater reliability for NASA and the nation's space program," said Jeb Brewster, project manager of the Friction Stir Welded Spun Formed Dome project at Lockheed Martin Space Systems. "This team has pushed the envelope by using existing commercial materials combined with cutting edge technology. The results provide the potential for a significant improvement over the current processes and materials being used today."

The spherical tank dome was manufactured from a flat plate "blank" made of the 2195 alloy. The blank was constructed by friction stir welding together two commercial off-the-shelf plates in order to produce a large starting blank, reducing the cost of raw materials. The welded plate blank was then spun formed to create the single-piece tank dome.

This is the first time this combination of twin manufacturing processes has been successfully applied to produce a full-scale 2195 aluminum-lithium dome.

The spherical tank dome was manufactured from a flat plate "blank" made of the 2195 alloy. The blank was constructed by friction stir welding together two commercial off-the-shelf plates in order to produce a large starting blank. The welded plate blank was then spun formed to create the single-piece tank dome. Image credit: MT Aerospace

"This achievement also demonstrates that international cooperation between the United States and Europe can achieve very promising and concrete results with mutual benefits for future space programs," said Judith Watson, program manager at NASA's Langley Research Center in Hampton, Va. "Lockheed Martin and MT Aerospace have set up a very efficient and effective development team."

Two additional, full-scale development tank domes are scheduled for manufacture and testing in coming months as part of the joint, two-year technology demonstration program.

NASA has invested in the Friction Stir Weld Spun Form Dome Project since 2006, which is managed by the Exploration Technology Development Program for NASA's Exploration Systems Mission Directorate in Washington.

Media Contact:
Kim Newton, NASA's Marshall Space Flight Center
kimberly.d.newton@nasa.gov

For more information visit http://www.nasa.gov/topics/technology/features/twin_dome.html

Orbiter Puts Itself Into Safe Standby

Mars Odyssey Mission Status Report

PASADENA, Calif. -- NASA's Mars Odyssey orbiter put itself into a safe standby mode on Saturday, Nov. 28, and the team operating the spacecraft has begun implementing careful steps designed to resume Odyssey's science and relay operations within about a week.

Engineers have diagnosed the cause of the Nov. 28 event as the spacecraft's proper response to a memory error with a known source. The likely cause is an upset in the orbiter's "memory error external bus," as was the case with a similar event in June 2008.

In safe mode over the weekend, Odyssey remained in communication with ground controllers and maintained healthy temperatures and power. To clear the memory error, the team commanded Odyssey today to perform a cold reboot of the orbiter's onboard computer. The spacecraft reported that the reboot had been completed successfully.

"This event is a type we have seen before, so we have a known and tested path to resuming normal operations," said Odyssey Project Manager Philip Varghese of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Artist concept of Mars Odyssey. Image credit: NASA/JPL

Odyssey has been orbiting Mars since 2001. In addition to its own major scientific discoveries and continuing studies of the planet, the Odyssey mission has played important roles in supporting the missions of the Mars rovers Spirit and Opportunity and the Phoenix Mars Lander.

Until Odyssey is available again as a communications relay, Spirit and Opportunity will be operating with direct communications to and from Earth.

JPL, a division of the California Institute of Technology in Pasadena, manages Mars Odyssey for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. Additional information about Odyssey is at http://www.nasa.gov/mission_pages/odyssey.

Media contact: Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

For more information visit http://www.nasa.gov/mission_pages/odyssey/odyssey-20091130.html

Another Stall of Right-Rear Wheel Ends Drive

Spirit's right-rear wheel stalled again on Sol 2099 (Nov. 28, 2009) during the first step of a two-step extrication maneuver. This stall is different in some characteristics from the stall on Sol 2092 (Nov. 21). The Sol 2099 stall occurred more quickly and the inferred rotor resistance was elevated at the end of the stall. Investigation of past stall events along with these characteristics suggest that this stall might not be result of the terrain, but might be internal to the right-rear wheel actuator. Rover project engineers are developing a series of diagnostics to explore the actuator health and to isolate potential terrain interactions. These diagnostics are not likely to be ready before Wednesday. Plans for future driving will depend on the results of the diagnostic tests.

This blink comparison aids evaluation of a drive by NASA's Mars Exploration Rover Spirit during the rover's 2,099th Martian day, or sol (Nov. 28, 2009). Image Credit: NASA/JPL-Caltech

Before the Sol 2099 drive ended, Spirit completed 1.4 meters of wheel spin and the rover's center moved 0.5 millimeters (0.02 inch) forward, 0.25 millimeters (0.01 inch) to the left and 0.5 millimeters (0.02 inch) downward. Since Spirit began extrication on Sol 2088, the rover has performed 9.5 meters (31 feet) of wheel spin and the rover's center, in total, has moved 16 millimeters (0.63 inch) forward, 10 millimeters (0.39 inch) to the left and 5 millimeters (0.20 inch) downward.

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer-20091201.html

Scientists Explain Puzzling Lake Asymmetry on Titan

PASADENA, Calif. -- Researchers at the California Institute of Technology, NASA's Jet Propulsion Laboratory, and other institutions suggest that the eccentricity of Saturn's orbit around the sun may be responsible for the unusually uneven distribution of lakes over the northern and southern polar regions of the planet's largest moon, Titan. A paper describing the theory appears in the Nov. 29 advance online edition of Nature Geoscience.

Saturn's oblong orbit around the sun exposes different parts of Titan to different amounts of sunlight, which affect cycles of precipitation and evaporation in those areas. Similar variations in Earth's orbit also drive long-term ice-age cycles on our planet.

As revealed by Synthetic Aperture Radar imaging data from NASA's Cassini spacecraft, liquid methane and ethane lakes in Titan's northern high latitudes cover 20 times more area than lakes in the southern high latitudes. The Cassini data also show there are significantly more partially filled and now-empty lakes in the north. (In the radar data, smooth features -- like the surfaces of lakes -- appear as dark areas, while rougher features -- such as the bottom of an empty lake-appear bright.) The asymmetry is not likely to be a statistical fluke because of the large amount of data collected by Cassini in its five years surveying Saturn and its moons.

Scientists initially considered the idea that "there is something inherently different about the northern polar region versus the south in terms of topography, such that liquid rains, drains or infiltrates the ground more in one hemisphere," said Oded Aharonson of Caltech, lead author of the Nature Geoscience paper.

However, Aharonson notes that there are no substantial known differences between the north and south regions to support this possibility. Alternatively, the mechanism responsible for this regional dichotomy may be seasonal. One year on Titan lasts 29.5 Earth years. Every 15 Earth years, the seasons of Titan reverse, so that it becomes summer in one hemisphere and winter in the other. According to this seasonal variation hypothesis, methane rainfall and evaporation vary in different seasons -- recently filling lakes in the north while drying lakes in the south.

The problem with this idea, Aharonson said, is that it accounts for decreases of about one meter per year in the depths of lakes in the summer hemisphere. But Titan's lakes are a few hundred meters deep on average, and wouldn't drain (or fill) in just 15 years. In addition, seasonal variation can't account for the disparity between the hemispheres in the number of empty lakes. The north polar region has roughly three times as many dried-up lake basins as the south and seven times as many partially filled ones.

"How do you move the hole in the ground?" Aharonson asked. "The seasonal mechanism may be responsible for part of the global transport of liquid methane, but it's not the whole story." A more plausible explanation, say Aharonson and his colleagues, is related to the eccentricity of the orbit of Saturn -- and hence of Titan, its satellite -- around the sun.

The northern and southern hemispheres of Titan, showing the great disparity between the abundance of lakes in the north and their paucity in the south. The hypothesis presented favors long-term flux of volatile hydrocarbons, predominantly methane, from hemisphere to hemisphere. Recently, the direction of transport has been from south to north, but the effect would have reversed tens of thousands of years ago. Credit: NASA/JPL/Caltech/UA/SAR

Like Earth and other planets, Saturn's orbit is not perfectly circular, but is instead somewhat elliptical and oblique. Because of this, during its southern summer, Titan is about 12 percent closer to the sun than during the northern summer. As a result, northern summers are long and subdued; southern summers are short and intense.

"We propose that, in this orbital configuration, the difference between evaporation and precipitation is not equal in opposite seasons, which means there is a net transport of methane from south to north," said Aharonson. This imbalance would lead to an accumulation of methane -- and hence the formation of many more lakes -- in the northern hemisphere.

This situation is only true right now, however. Over very long time scales of tens of thousands of years, Saturn's orbital parameters vary, at times causing Titan to be closer to the sun during its northern summer and farther away in southern summers, and producing a reverse in the net transport of methane. This should lead to a buildup of hydrocarbon -- and an abundance of lakes -- in the southern hemisphere.

"Like Earth, Titan has tens-of-thousands-of-year variations in climate driven by orbital motions," Aharonson said. On Earth, these variations, known as Milankovitch cycles, are linked to changes in solar radiation, which affect global redistribution of water in the form of glaciers, and are believed to be responsible for ice-age cycles. "On Titan, there are long-term climate cycles in the global movement of methane that make lakes and carve lake basins. In both cases we find a record of the process embedded in the geology," he added.

"We may have found an example of long-term climate change, analogous to Milankovitch climate cycles on Earth, on another object in the solar system," he said.

The paper's co-authors are Caltech graduate student Alexander G. Hayes; Jonathan I. Lunine, Lunar and Planetary Laboratory, Tucson, Ariz.; Ralph D. Lorenz, Applied Physics Laboratory at the Johns Hopkins University, Laurel, Md.; Michael D. Allison, NASA Goddard Institute for Space Studies, New York; and Charles Elachi, director of JPL. The work was partially funded by the Cassini Project.

For more information about the Cassini-Huygens mission, visit: http://www.nasa.gov/cassini or http://saturn.jpl.nasa.gov/index.cfm . 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 in Washington, D.C.


Jia-Rui C. Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
jia-rui.c.cook@jpl.nasa.gov

Stephen Cole 202-657-2194
Headquarters, Washington
stephen.e.cole@nasa.gov

For more information visit http://www.nasa.gov/mission_pages/cassini/media/cassini-20091130.html

Expedition 21 Crew Lands in Kazakhstan; Space Junk No Threat to Station

As the International Space Station’s smaller, two-person, Expedition 22 crew enjoyed its first full day alone in orbit Tuesday, Mission Control monitored a small piece of space junk until tracking updates showed it would not come close enough to require precautions.

At 11:25 a.m. EST, Flight Director Dana Weigel decided not to awaken the crew based on the latest tracking data on the piece of a Russian Cosmos satellite, estimated to be less than four inches in diameter. Mission Control determined the probability of a collision was so low that there was no need to have the crew make a precautionary move into their Soyuz spacecraft, close hatches and be ready to depart the station.

The debris had been so small that tracking sensors initially had trouble providing reliable information about how close it might come to the station, but best estimates were that the closest approach would be about 1 kilometer away at 1:19 p.m.

Commander Jeff Williams and Flight Engineer Max Suraev were informed of the possible close pass before they went to bed at 2:30 a.m. following the departure of crewmates Frank De Winne, Roman Romanenko and Bob Thirsk who returned to Earth aboard their Soyuz TMA-15 spacecraft northeast of Arkalyk, Kazakhstan at 2:15 a.m. (1:15 p.m. Kazakhstan time). Williams and Suraev were scheduled to enjoy the first of two full days off Tuesday.

The U.S. Space Command routinely tracks space debris in orbit around the Earth, and reports to NASA any possible "conjunctions" or close passes to the space station.

NASA has a set of long-standing guidelines that are used to assess whether the threat of such a close pass is sufficient to warrant evasive action or precautions to ensure the safety of the crew.

These guidelines essentially draw an imaginary box, known as the "pizza box" because of its flat, rectangular shape, around the space station. This box is about half a mile deep by 15 miles across by 15 miles tall (0.75 x 25 x 25 kilometers). When predictions indicate that the debris will pass close enough for concern and the quality of the tracking data is deemed sufficiently accurate, Mission Control centers in Houston and Moscow work together to develop a prudent course of action.

Image above: Kazakh authorities give a warm welcome to the Expedition 21 crew members following their return to Earth aboard the Soyuz TMA-15 spacecraft. Pictured, left to right, are Canadian Space Agency astronaut Robert Thirsk, flight engineer; Russian cosmonaut Roman Romanenko, flight engineer; and European Space Agency astronaut Frank De Winne. Photo credit: ESA/Stephane Corvaja

Sometimes these encounters are known well in advance and there is time to move the station slightly, known as a "debris avoidance maneuver" to keep the debris outside of the box. Other times, the tracking data isn’t precise enough to warrant such a maneuver or the close pass isn’t identified in time to make the maneuver. In those cases, the control centers may agree that the best course of action is to move the crew into the Soyuz spacecraft that are used to transport crew members to and from the station so that they could isolate those spaceships from the station by closing hatches, and then leave the station if the debris were to collide with the station and cause a loss of pressure in the life-supporting module. The Soyuz act as lifeboats for crew members in the event of an emergency.

Mission Control also has the option of taking additional precautions, such as closing hatches between some of the station’s modules, if the likelihood of a collision is great enough.

If the tracking data indicates any extra precautions are needed updates will be provided on the web and NASA TV as appropriate.

Meanwhile, De Winne, Romanenko and Thirsk were met by the Russian Search and Recovery Forces in all-terrain vehicles and were extracted quickly from the upright Soyuz. Russian helicopters normally used for recovery operations were grounded due to low clouds and freezing temperatures.

After being extracted from the Soyuz, the crew was then driven back to Arkalyk to spend the night. On Wednesday (Tuesday night, U.S. time), the crew will helicopter from Arkalyk to Kustanai, and then fly on the Gagarin Cosmonaut Training Center plane to Chkalovsky Airfield near their training base in Star City, Russia, outside Moscow for reunions with their families and dignitaries and the start of a rehabilitation period. Flight surgeons report that the crew is in excellent shape.

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

WISE Snug in Its Nose Cone

NASA's Wide-field Infrared Survey Explorer has been wrapped in the outer nose cone, or "fairing," that will protect it during its scheduled Dec. 9 launch from Vandenberg Air Force Base, Calif.

The fairing will split open like a clamshell about five minutes after launch. The spacecraft will circle Earth over the poles, scanning the entire sky one-and-a-half times in nine months. The mission will uncover hidden cosmic objects, including the coolest stars, dark asteroids and the most luminous galaxies.

WISE is shown inside one-half of the nose cone, or fairing, that will protect it during launch. The spacecraft is clamped to the top of the rocket above the white conical fitting. The fairing will split open like a clamshell about five minutes after launch. Credit: United Launch Alliance/ JPL-Caltech/JPL-Caltech

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages WISE for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

More information is online at http://www.nasa.gov/wise and http://wise.astro.ucla.edu .

For more information visit http://www.nasa.gov/mission_pages/WISE/news/wiseb20091130.html

Dusty Beginnings of a Star

This artist's rendering gives us a glimpse into a cosmic nursery as a star is born from the dark, swirling dust and gas of this cloud. Stars form when dark dust from the cloud begins to clump together under the influence of its own gravity. The infalling material forms a disk as it spirals inward, which feeds material onto the forming star at its center. Jets of material that shoot from the inner disk and protostar herald its birth.

Planets form out of the remnants of the disk of material that surrounds the infant star. This leads to a question that has long perplexed astronomers about the nature of brown dwarfs, objects that fall between planets and stars in terms of their temperature and mass.

Are brown dwarfs born like stars, as in this rendering, or do they form like planets orbiting another star? A study by researchers using data from NASA's Spitzer Space Telescope has led to the preliminary conclusion that they are formed much like the star you see here.

Image credit: NASA/JPL-Caltech

For more information visit http://www.nasa.gov/mission_pages/spitzer/multimedia/spitzer20091123-b.html

Space Shuttle Atlantis Crew Set to Land in Florida Friday

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis and its seven-member crew are expected to return to Earth on Friday, Nov. 27, after an 11-day mission. The two landing opportunities at NASA's Kennedy Space Center in Florida are at 9:44 a.m. and 11:19 a.m. EST.

NASA will evaluate weather conditions at Kennedy before permitting Atlantis and its crew to land. If bad weather prevents a return to Florida on Friday or Saturday, both Kennedy and the backup landing site at Edwards Air Force Base in California will be activated for consideration on Sunday. For recorded updates about the shuttle landing, call 321-867-2525.

Approximately two hours after landing, NASA officials will hold a briefing to discuss the mission. The participants will be:

- Bill Gerstenmaier, NASA associate administrator for Space Operations
- Mike Moses, space shuttle launch integration manager
- Mike Leinbach, NASA shuttle launch director

After touchdown in Florida, the astronauts will undergo physical examinations and meet with their families. They are expected to make brief remarks at the runway and hold a news conference approximately six hours after landing. The news events will be broadcast live on NASA Television and the agency's Web site.

The Kennedy news center will open for landing activities at 5 a.m. Friday and close at 5 p.m., or one hour after the last media event.

The STS-129 media badges are in effect through landing. The media accreditation building on State Road 3 will be open Friday from 6 a.m. to 8:30 a.m. The last bus will depart from the news center for the Shuttle Landing Facility one hour before landing.

If the landing is diverted to Edwards, reporters should call NASA's Dryden Flight Research Center public affairs office at 661-276-3449. Dryden has limited facilities available for previously accredited journalists.

The NASA News Twitter feed is updated throughout the shuttle mission and landing. To access the feed, visit:

http://www.twitter.com/nasa

For NASA TV downlink information, schedules and links to streaming video, visit:

http://www.nasa.gov/ntv

For the latest information about the STS-129 mission and accomplishments, visit:

http://www.nasa.gov/shuttle

Space Shuttle Crew Returns Home after 11-Day Mission

CAPE CANAVERAL, Fla. -- Space shuttle Atlantis and its crew of seven astronauts ended an 11-day journey of nearly 4.5 million miles with a 9:44 a.m. EST landing Friday at NASA's Kennedy Space Center in Florida.

The mission, designated STS-129, included three spacewalks and the installation of two platforms to the International Space Station's truss, or backbone. The platforms hold large spare parts to sustain station operations after the shuttles are retired. The shuttle crew delivered about 30,000 pounds of replacement parts for systems that provide power to the station, keep it from overheating, and maintain a proper orientation in space.

STS-129 Commander Charlie Hobaugh was joined on Atlantis' STS-129 mission by Pilot Barry Wilmore and Mission Specialists Leland Melvin, Randy Bresnik, Mike Foreman and Bobby Satcher. Atlantis returned with station resident Nicole Stott, who spent 91 days in space. This marks the final time the shuttle is expected to rotate station crew members.

A welcome ceremony for the astronauts will be held Monday, Nov. 30, in Houston. The public is invited to attend the 4 p.m. CST event at Ellington Field's NASA Hangar 990. Highlights from the ceremony will be broadcast on NASA Television's Video File. For NASA TV downlink information, schedules and links to streaming video, visit:

http://www.nasa.gov/ntv

With Atlantis and its crew safely home, the stage is set for launch of shuttle Endeavour on its STS-130 mission, targeted to begin in February. Endeavour will deliver a pressurized module, known as Tranquility, which will provide room for many of the space station's life support systems. Attached to the node is a cupola, a robotic control station with six windows around its sides and another in the center that provides a 360-degree view around the station.

For more about the STS-129 mission and the upcoming STS-130 flight, visit:

http://www.nasa.gov/shuttle

STS-129 crew members Melvin, Satcher and Stott are providing mission updates on Twitter. For their Twitter feeds and other NASA social media Web sites, visit:

http://www.nasa.gov/connect

For information about NASA and agency programs, visit:

http://www.nasa.gov

The Way Home

Seen over the Mediterranean Sea, near the Algerian coast, the space shuttle Atlantis is featured in this image photographed by the Expedition 21 crew on the International Space Station soon after the shuttle and station began their post-undocking separation. Undocking of the two spacecraft occurred at 4:53 a.m. EST on Nov. 25, 2009.

Image Credit: NASA

For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1530.html

Fermi Telescope Peers Deep into Microquasar

Goddard Release No. 09-82

NASA's Fermi Gamma-ray Space Telescope has made the first unambiguous detection of high-energy gamma-rays from an enigmatic binary system known as Cygnus X-3. The system pairs a hot, massive star with a compact object -- either a neutron star or a black hole -- that blasts twin radio-emitting jets of matter into space at more than half the speed of light.

Astronomers call these systems microquasars. Their properties -- strong emission across a broad range of wavelengths, rapid brightness changes, and radio jets -- resemble miniature versions of distant galaxies (called quasars and blazars) whose emissions are thought to be powered by enormous black holes.

In Cygnus X-3, an accretion disk surrounding a black hole or neutron star orbits close to a hot, massive star. Gamma rays (purple, in this illustration) likely arise when fast-moving electrons above and below the disk collide with the star's ultraviolet light. Fermi sees more of this emission when the disk is on the far side of its orbit. Credit: NASA's Goddard Space Flight Center

"Cygnus X-3 is a genuine microquasar and it's the first for which we can prove high-energy gamma-ray emission," said Stéphane Corbel at Paris Diderot University in France.

The system, first detected in 1966 as among the sky's strongest X-ray sources, was also one of the earliest claimed gamma-ray sources. Efforts to confirm those observations helped spur the development of improved gamma-ray detectors, a legacy culminating in the Large Area Telescope (LAT) aboard Fermi.

At the center of Cygnus X-3 lies a massive Wolf-Rayet star. With a surface temperature of 180,000 degrees F, or about 17 times hotter than the sun, the star is so hot that its mass bleeds into space in the form of a powerful outflow called a stellar wind. "In just 100,000 years, this fast, dense wind removes as much mass from the Wolf-Rayet star as our sun contains," said Robin Corbet at the University of Maryland, Baltimore County.

Brighter colors indicate greater numbers of gamma rays detected in this Fermi LAT view of a region centered on the position of Cygnus X-3 (circled). The brightest sources are pulsars. Credit: NASA/DOE/Fermi LAT Collaboration

Every 4.8 hours, a compact companion embedded in a disk of hot gas wheels around the star. "This object is most likely a black hole, but we can't yet rule out a neutron star," Corbet noted.

Fermi's LAT detects changes in Cygnus X-3's gamma-ray output related to the companion's 4.8-hour orbital motion. The brightest gamma-ray emission occurs when the disk is on the far side of its orbit. "This suggests that the gamma rays arise from interactions between rapidly moving electrons above and below the disk and the star's ultraviolet light," Corbel explained.

When ultraviolet photons strike particles moving at an appreciable fraction of the speed of light, the photons gain energy and become gamma rays. "The process works best when an energetic electron already heading toward Earth suffers a head-on collision with an ultraviolet photon," added Guillaume Dubus at the Laboratory for Astrophysics in Grenoble, France. "And this occurs most often when the disk is on the far side of its orbit."

This image locates the view around Cygnus X-3 within Fermi's all-sky map. Credit: NASA/DOE/Fermi LAT Collaboration

Through processes not fully understood, some of the gas falling toward Cygnus X-3's compact object instead rushes outward in a pair of narrow, oppositely directed jets. Radio observations clock gas motion within these jets at more than half the speed of light.

Between Oct. 11 and Dec. 20, 2008, and again between June 8 and Aug. 2, 2009, Cygnus X-3 was unusually active. The team found that outbursts in the system's gamma-ray emission preceded flaring in the radio jet by roughly five days, strongly suggesting a relationship between the two.

The findings, published today in the electronic edition of Science, will provide new insight into how high-energy particles become accelerated and how they move through the jets.

Related Links:

› Fermi Telescope Caps First Year With Glimpse of Space-Time
› Gamma-Rays from High-Mass X-Ray Binaries

Francis Reddy
NASA's Goddard Space Flight Center

For more information visit http://www.nasa.gov/mission_pages/GLAST/news/fermi-cygnus.html

New Report Provides Update on Recent Climate Changes

A new global scientific synthesis report prepared by 26 of the world's top climate scientists, including JPL research scientist Eric Rignot and NASA Goddard Space Flight Center researcher Robert Bindschadler, concludes that several important aspects of climate change are occurring at the high end of, or even beyond the expectations of just a few years ago.

View of the Earth as seen by the Apollo 17 crew traveling toward the moon. Image credit: NASA

The report, "The Copenhagen Diagnosis: Updating the World on the Latest Climate Science," documents key findings in climate change science since December 2005. That was the cutoff for scientific inputs used to prepare the United Nations' Intergovernmental Panel on Climate Change Fourth Assessment Report, released in 2007.

› Read the news release

› Read the full report

For more information visit http://www.nasa.gov/topics/earth/features/rignot20091124.html

Approaching 'Marquette Island'

NASA's Mars Exploration Rover Opportunity took this picture of a rock informally named "Marquette Island" as the rover was approaching the rock for investigations that have suggested the rock is a stony meteorite.

Opportunity used its navigation camera to record this image during the 2,056th Martian day, or sol, of the rover's mission on Mars (Nov. 5, 2009).

The dark-toned rock stood out so prominently in more distant views on earlier sols that the rover team referred to it as "Sore Thumb" before assigning the Marquette name in accord with an informal naming convention of choosing island names for the isolated rocks that the rover is finding as it crosses a relatively barren plain on its long trek from Victoria Crater toward Endeavour Crater.

Image Credit: NASA/JPL-Caltech

For more information visit http://www.nasa.gov/mission_pages/mer/multimedia/merB-20091125.html

No Wheel Stall in Diagnostic Drive

On Sol 2095 (Tuesday, Nov. 24), Spirit performed a set of diagnostic actions related to a stall of the right-rear wheel on the previous drive, three days earlier. The diagnostics showed a fully functioning wheel free of obstruction. The rover was commanded forward with 1.5 meters (4.9 feet) of wheel spin. The rover moved 2.1 millimeters (0.08 inch) forward, 1.1 millimeters (0.04 inch) to the left, and 0.3 millimeters (0.01 inch) down.

The cumulative results from Sols 2088 to 2095 (Nov. 17 to 24) are 8.1 meters (27 feet) of commanded motion, 15.7 millimeters (0.6 inch) of forward progress, 9.9 millimeters (0.4 inch) of movement to the left, and 4.8 millimeters (0.2 inch) of sinkage.

This view from the navigation camera near the top of the mast on NASA's Mars Exploration Rover Spirit shows the tracks left by the rover as it drove southward and backward, dragging its inoperable right-front wheel, to the location where the rover broke through a crust in April 2009 and became embedded in soft sand.Image Credit: NASA/JPL-Caltech

The plan for a drive during the long holiday weekend is another two-step drive, with each step 2.5 meters (8.2 feet) of commanded wheel spin. All wheels will be straight and run at the same speed. Results of this commanded drive will be analyzed Monday, Nov. 30.

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer-20091125.html

Prometheus Plays Tug of War with One of Saturn's Rings

The diminutive moon Prometheus whips gossamer ice particles out of Saturn's F ring in this image taken by the Cassini spacecraft on Aug. 21, 2009. The moon and the ring have eccentric, offset orbits, so Prometheus dips in and out of the F ring as it travels around Saturn. Its gravitational force drags the dust-sized particles at the edge of the F ring along for the ride.

Saturn's moon Prometheus, orbiting near the streamer-channels it has created in the thin F ring, casts a shadow on the A ring in this image taken a little more than a week after the planet's August 2009 equinox. Image credit: NASA/JPL/Space Science Institute

The ability of the potato-shaped Prometheus to pull material out of the F ring was first theorized in the late 1990s and finally imaged by Cassini in 2004. But because these so-called "streamer-channels" have constantly shifted as Prometheus and the F ring have moved, the F ring has never looked the same twice. The gravitational pull of other moons on other rings has created waves in the edges, but nothing quite as extreme as the streamer-channels of Prometheus.

For more information visit http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20091125.html

Examining 'Marquette Island'

NASA's Mars Exploration Rover Opportunity used the wire brush of its rock abrasion tool during the rover's 2,070th Martian day, or sol (Nov. 19, 2009), to scour dust from a circular target area on a rock called "Marquette Island." The brushed target area, called "Peck Bay," is visible as a dark circle about 5 centimeters (2 inches) in diameter just below the tool turret at the end of the rover's robotic arm in this image. The image was taken later the same sol by the rover's front hazard-avoidance camera.

Opportunity is performing an extensive analysis of this rock, which initial investigation suggests may be a stony meteorite.

Image Credit: NASA/JPL-Caltech

For more information visit http://www.nasa.gov/mission_pages/mer/multimedia/merA-20091125.html