Spooky Creatures on the Prowl

The Cassini-Huygens team sends "best witches" for a happy, healthy and fun Halloween. Cassini's first four years at Saturn have bedazzled with stunning images and exciting results. With the start of the Equinox mission, the team promises to scare up many more treats as they continue studying the eerie glow of Saturn's rings, the spine-tingling thunder on the planet, the hair-raising jets on Enceladus, and the murky brew on Titan. A full view of their ghostly Saturn can be seen at
http://saturn.jpl.nasa.gov/multimedia/images/image-details.cfm?imageID=3293

Closer to home, ghoulish phantoms appear to haunt Earth's middle atmosphere in this enhanced depiction of water vapor derived from an animation of NASA Aqua Atmospheric Infrared Sounder data. To watch the animation, go to
http://airs.jpl.nasa.gov/story_archive/Ghostly_Images_in_Earths_Water_Vapor/

For some eerie sounds, visit our spooky sounds from space at
http://www.jpl.nasa.gov/multimedia/sounds2/index-flash.html .

NASA to Hold Small Business Symposium

NASA will host the inaugural Small Business Symposium and Awards Ceremony Nov. 17-18 in Washington at the Hilton Washington, 1919 Connecticut Ave., NW. Participation in this symposium is open to industry, academia and domestic small businesses. The deadline to register for the symposium is Nov. 3.

The Business Opportunities Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and NASA's Office of Small Business Programs at NASA Headquarters in Washington are hosting the event.

Attendees will have the opportunity to network with NASA and its prime contractors and learn how to do business with the agency. NASA representatives will discuss plans for future Earth and space missions as well as other agency programs, initiatives, and business opportunities. NASA will provide information about the skills, resources and technologies needed to achieve NASA's missions, programs and research.

Topics at this two-day event include information about NASA's Mentor-Protege Program, how NASA's Small Business Program works, how to reach NASA's prime contractors for subcontracting opportunities, and how small businesses can build a high-tech industrial base.

NASA's Small Business Industry and Advocate awards will be presented on the symposium's second day. The awards recognize outstanding contributions made by NASA employees and industry representatives to support the agency's small business program.

To register for the symposium, visit http://acquisition.jpl.nasa.gov/boo/2008sbsym/index.asp . For more information about the NASA-JPL Small Business Symposium, contact Andrea Acosta at andrea.e.acosta@jpl.nasa.gov or 818-354-7531.

More information about NASA's Office of Small Business Programs is at: http://www.osbp.nasa.gov . More information about JPL's Business Opportunities Office is at: http://acquisition.jpl.nasa.gov/boo .

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

NASA MEASUREMENTS SHOW GREENHOUSE GAS METHANE ON THE RISE AGAIN

The amount of methane in Earth's atmosphere shot up in 2007, bringing to an end approximately a decade in which atmospheric levels of the potent greenhouse gas were essentially stable. The new study is based on data from a worldwide NASA-funded measurement network.

Methane levels in the atmosphere have more than tripled since pre-industrial times, accounting for around one-fifth of the human contribution to greenhouse gas-driven global warming. Until recently, the leveling off of methane levels had suggested that the rate of its emission from Earth's surface was being approximately balanced by the rate of its destruction in the atmosphere.

However, the balance has been upset since early 2007, according to research published this week in the American Geophysical Union's "Geophysical Review Letters." The paper's lead authors, Matthew Rigby and Ronald Prinn of the Massachusetts Institute of Technology, say this imbalance has resulted in several million metric tons of additional methane in the atmosphere.

Methane is produced by wetlands, rice paddies, cattle, and the gas and coal industries. It is destroyed in the atmosphere by reaction with the hydroxyl free radical, often referred to as the atmosphere's "cleanser."

"This increase in methane is worrisome because the recent stability of methane levels was helping to compensate for the unexpectedly fast growth of carbon dioxide emissions," said climate modeler Drew Shindell at NASA's Goddard Institute for Space Studies in New York.

"If methane continues to increase rapidly, we'll lose that offsetting effect. We will use NASA's climate modeling capability to improve our understanding of what is causing the increase and project future methane levels."

One surprising feature of this recent growth is that it occurred almost simultaneously at all measurement locations across the globe. However, the majority of methane emissions are in the Northern Hemisphere, and it takes more than one year for gases to be mixed between the hemispheres. Theoretical analysis of the measurements shows that if an increase in emissions is solely responsible, these emissions must have risen by a similar amount in both hemispheres at the same time.

The scientists analyzed air samples collected by the NASA-funded Advanced Global Atmospheric Gases Experiment ground network from 1997 through April 2008. The network was created in the 1970s in response to international concerns about chemicals depleting the ozone layer. It is supported by NASA as part of its congressional mandate to monitor ozone-depleting trace gases, many of which also are greenhouse gases. Air samples are collected and analyzed at several stations around the world.

According to the researchers, a rise in Northern Hemispheric emissions may be a result of very warm conditions over Siberia throughout 2007, potentially leading to increased bacterial emissions from wetland areas. However, a potential cause for an increase in Southern
Hemispheric emissions is less clear.

An alternative explanation for the rise may lie, at least in part, with a drop in the concentrations of the methane-destroying hydroxyl free radical. Theoretical studies show that if this has happened, the required global methane emissions rise would have been smaller and more strongly biased to the Northern Hemisphere. At present, however, it is uncertain whether such a drop in hydroxyl free radical concentrations did occur.

"The next step to pin down the cause of the methane increase will be to study this using a very high-resolution atmospheric circulation model and additional measurements from other networks," Prinn said. "The key is to determine more precisely the relative roles of increased methane emission versus a decrease in the rate of removal. Apparently we have a mix of the two, but we want to know how much of each is responsible for the overall increase."

It is too early to tell whether this increase represents a return to sustained methane growth, or the beginning of a relatively short-lived anomaly, according to Rigby and Prinn. Given that methane is about 25 times stronger as a greenhouse gas per metric ton of emissions than carbon dioxide, the situation will require careful monitoring in the near future to better understand methane's impact on future climate change.

For information about NASA and agency programs, visit:

http://www.nasa.gov

MESSENGER SPACECRAFT REVEALS MORE HIDDEN TERRITORY ON MERCURY

A NASA spacecraft gliding over the battered surface of Mercury for the second time this year has revealed more previously unseen real estate on the innermost planet. The probe also has produced several science firsts and is returning hundreds of new photos and measurements of the planet's surface, atmosphere and magnetic field.

The MErcury Surface, Space ENvironment, GEochemistry, and Ranging, or MESSENGER, spacecraft flew by Mercury shortly after 4:40 a.m. EDT, on Oct. 6. It completed a critical gravity assist to keep it on course to orbit Mercury in 2011 and unveiled 30 percent of Mercury's surface never before seen by a spacecraft.

"The region of Mercury's surface that we viewed at close range for the first time this month is bigger than the land area of South America," said Sean Solomon, principal investigator and director of the Department of Terrestrial Magnetism at the Carnegie Institution of Washington. "When combined with data from our first flyby and from Mariner 10, our latest coverage means that we have now seen about 95 percent of the planet."

The spacecraft's science instruments operated throughout the flyby. Cameras snapped more than 1,200 pictures of the surface, while topography beneath the spacecraft was profiled with a laser altimeter. The comparison of magnetosphere observations from the spacecraft's first flyby in January with data from the probe's second pass has provided key new insight into the nature of Mercury's internal magnetic field and revealed new features of its magnetosphere. The magnetosphere is the volume surrounding Mercury that is controlled by the planet's magnetic field.

"The previous flybys by MESSENGER and Mariner 10 provided data only about Mercury's eastern hemisphere," explains Brian Anderson of the Johns Hopkins University Applied Physics Laboratory, known as APL, in Laurel, Md. "The most recent flyby gave us our first measurements on Mercury's western hemisphere, and with them we discovered that the
planet's magnetic field is highly symmetric."

The probe's Mercury Laser Altimeter, or MLA, measured the planet's topography, allowing scientists, for the first time, to correlate high-resolution topography measurements with high-resolution images.

"The MLA collected altimetry in regions where images from MESSENGER and Mariner 10 data are available, and new images were obtained of the region sampled by the altimeter in January," said Maria Zuber, co-investigator and head of the Department of Earth, Atmospheric, and Planetary Sciences at the Massachusetts Institute of Technology. "These topographic measurements now improve considerably the ability to interpret surface geology."

The Mercury Atmospheric and Surface Composition Spectrometer observed Mercury's thin atmosphere, known as an exosphere. The instrument searched for emissions from sodium, calcium, magnesium, and hydrogen atoms. Observations of magnesium are the first detection of this chemical in Mercury's exosphere. Preliminary analysis suggests that the spatial distributions of sodium, calcium, and magnesium are different. Simultaneous observations of these spatial distributions, also a first for the spacecraft, have opened an unprecedented window into the interaction of Mercury's surface and exosphere.

Spacecraft images also are revealing for the first time vast geologic differences on the surface.

"Now that MESSENGER's cameras have imaged more than 80 percent of Mercury, it is clear that, unlike the moon and Mars, Mercury's surface is more homogeneously ancient and heavily cratered, with large extents of younger volcanic plains lying within and between giant impact basins," said co-investigator Mark Robinson of Arizona State University in Tempe.

The project is the seventh in NASA's Discovery Program of lower-cost, scientifically focused missions. APL designed, built and operates the spacecraft and manages the mission for NASA's Science Mission Directorate in Washington. Science instruments were built by APL; NASA's Goddard Space Flight Center in Greenbelt, Md.; the University of Michigan, Ann Arbor; and the University of Colorado, Boulder. GenCorp Aerojet of Sacramento, Calif., and Composite Optics Inc. of San Diego, provided the propulsion system and composite structure.

For more information about the Mercury mission, visit:

www.nasa.gov/messenger

NASA TO DISCUSS STATUS OF HUBBLE SERVICING MISSION THURSDAY

NASA will host a media teleconference at 5 p.m. EDT on Thursday, Oct. 30, to discuss the status of the upcoming shuttle servicing mission to the Hubble Space Telescope. The fifth and final "house call" by astronauts to the telescope originally was planned for Oct. 10 but was postponed due to an onboard computer anomaly.

The briefing participants are:
- Jon Morse, director of the Astrophysics Division in NASA's Science Mission Directorate at NASA Headquarters in Washington
- Preston Burch, Hubble Space Telescope manager at NASA's Goddard Space Flight Center in Greenbelt, Md.

To participate in the teleconference, reporters in the U.S. should call 1-888-469-0494 and use the passcode "Hubble." International reporters should call 1-415-228-3905.

Approximately one hour after the briefing concludes, a recorded replay of the conference will be available by calling 1-888-458-8114. International callers can hear the replay by calling 1-402-998-1352.

Audio of the teleconference will be streamed live on the Internet at:

http://www.nasa.gov/newsaudio

NASA TV PROVIDES HD FEED OF DOCUMENTARY ON NASA'S FIRST 50 YEARS

NASA Television will provide a high definition feed of the documentary "50 Years of Exploration: The Golden Anniversary of NASA" on Thursday, Oct. 30, at 1 and 8 p.m. EDT.

Hosted by Neil Armstrong, the 90-minute documentary features film and video highlights of the agency's first half-century, as well as the insights and perspectives of astronauts, scientists, engineers and others whose contributions have helped shepherd America's space program.

Among the interviewees are former NASA astronaut and U.S. Senator John Glenn, Apollo Flight Director Gene Kranz, author Ray Bradbury, NASA scientist and Nobel Prize winner John Mather, and presidents George H.W. Bush and Bill Clinton.

"50 Years of Exploration: The Golden Anniversary of NASA" is a production of NASA Television. It will be re-fed on Friday, Oct. 31, at 10 a.m. and 2 p.m.

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

http://www.nasa.gov/ntv

NASA Phoenix Mission Status Report

NASA'S Phoenix Mars Lander entered safe mode late yesterday in response to a low-power fault brought on by deteriorating weather conditions. While engineers anticipated that a fault could occur due to the diminishing power supply, the lander also unexpectedly switched to the "B" side of its redundant electronics and shut down one of its two batteries.

During safe mode, the lander stops non-critical activities and awaits further instructions from the mission team. Within hours of receiving information of the safing event, mission engineers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and at Lockheed Martin in Denver, were able to send commands to restart battery charging. It is not likely that any energy was lost.

Weather conditions at the landing site in the north polar region of Mars have deteriorated in recent days, with overnight temperatures falling to -141F (-96C), and daytime temperatures only as high as -50F (-45C), the lowest temperatures experienced so far in the mission. A mild dust storm blowing through the area, along with water-ice clouds, further complicated the situation by reducing the amount of sunlight reaching the lander's solar arrays, thereby reducing the amount of power it could generate. Low temperatures caused the lander's battery heaters to turn on Tuesday for the first time, creating another drain on precious power supplies.

Science activities will remain on hold for the next several days to allow the spacecraft to recharge and conserve power. Attempts to resume normal operations will not take place before the weekend.

"This is a precarious time for Phoenix," said Phoenix Project Manager Barry Goldstein of JPL. "We're in the bonus round of the extended mission, and we're aware that the end could come at any time. The engineering team is doing all it can to keep the spacecraft alive and collecting science, but at this point survivability depends on some factors out of our control, such as the weather and temperatures on Mars."

The ability to communicate with the spacecraft has not been impacted. However, the team decided to cancel communication sessions Wednesday morning in order to conserve spacecraft power. The next communication pass is anticipated at 9:30 p.m. PDT Wednesday.

Yesterday, the mission announced plans to turn off four heaters, one at a time, in an effort to preserve power. The faults experienced late Tuesday prompted engineers to command the lander to shut down two heaters instead of one as originally planned. One of those heaters warmed electronics for Phoenix's robotic arm, robotic-arm camera, and thermal and evolved-gas analyzer (TEGA), an instrument that bakes and sniffs Martian soil to assess volatile ingredients. The second heater served the lander's pyrotechnic initiation unit, which hasn't been used since landing. By turning off selected heaters, the mission hopes to preserve power and prolong the use of the lander's camera and meteorological instruments.

Originally scheduled to last 90 days, Phoenix has completed a fifth month of exploration in the Martian arctic. As the Martian northern hemisphere shifts from summer to autumn, the lander was expected to generate less power due to fewer hours of sunlight reaching its solar panels. "It could be a matter of days, or weeks, before the daily power generated by Phoenix is less than needed to operate the spacecraft," said JPL mission manager Chris Lewicki. "We have only a few options left to reduce the energy usage."

The Phoenix mission is led by Peter Smith of the University of Arizona, Tucson, with project management at the Jet Propulsion Laboratory and development partnership at Lockheed Martin, Denver. International contributions come from the Canadian Space Agency; the University of Neuchatel, Switzerland; the universities of Copenhagen and Aarhus in Denmark; the Max Planck Institute in Germany; and the Finnish Meteorological Institute. The California Institute of Technology in Pasadena manages JPL for NASA.

NASA's Phoenix Mission Faces Survival Challenges

In a race against time and the elements, engineers with NASA's Phoenix Mars Lander mission hope to extend the lander's survival by gradually shutting down some of its instruments and heaters, starting today.

Originally scheduled to last 90 days, Phoenix has completed a fifth month of exploration in the Martian arctic. As expected, with the Martian northern hemisphere shifting from summer to fall, the lander is generating less power due to shorter days and fewer hours of sunlight reaching its solar panels. At the same time, the spacecraft requires more power to run several survival heaters that allow it to operate even as temperatures decline.

"If we did nothing, it wouldn't be long before the power needed to operate the spacecraft would exceed the amount of power it generates on a daily basis," said Phoenix Project Manager Barry Goldstein of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "By turning off some heaters and instruments, we can extend the life of the lander by several weeks and still conduct some science."

Over the next several weeks, four survival heaters will be shut down, one at a time, in an effort to conserve power. The heaters serve the purpose of keeping the electronics within tested survivable limits. As each heater is disabled, some of the instruments are also expected to cease operations. The energy saved is intended to power the lander's main camera and meteorological instruments until the very end of the mission.

Later today, engineers will send commands to disable the first heater. That heater warms Phoenix's robotic arm, robotic-arm camera, and thermal and evolved-gas analyzer (TEGA), an instrument that bakes and sniffs Martian soil to assess volatile ingredients. Shutting down this heater is expected to save 250 watt-hours of power per Martian day.

The Phoenix team has parked the robotic arm on a representative patch of Martian soil. No additional soil samples will be gathered. The thermal and electrical-conductivity probe (TECP), located on the wrist of the arm, has been inserted into the soil and will continue to measure soil temperature and conductivity, along with atmospheric humidity near the surface. The probe does not need a heater to operate and should continue to send back data for weeks.

Throughout the mission, the lander's robotic arm successfully dug and scraped Martian soil and delivered it to the onboard laboratories. "We turn off this workhorse with the knowledge that it has far exceeded expectations and conducted every operation asked of it," said Ray Arvidson, the robotic arm's co-investigator, and a professor at Washington University, St. Louis.

When power levels necessitate further action, Phoenix engineers will disable a second heater, which serves the lander's pyrotechnic initiation unit. The unit hasn't been used since landing, and disabling its heater is expected to add four to five days to the mission's lifetime. Following that step, engineers would disable a third heater, which warms Phoenix's main camera -- the Surface Stereo Imager –and the meteorological suite of instruments. Electronics that operate the meteorological instruments should generate enough heat on their own to keep most of those instruments and the camera functioning.

In the final step, Phoenix engineers may turn off a fourth heater -- one of two survival heaters that warm the spacecraft and its batteries. This would leave one remaining survival heater to run out on its own.

"At that point, Phoenix will be at the mercy of Mars," said Chris Lewicki of JPL, lead mission manger.

Engineers are also preparing for solar conjunction, when the sun is directly between Earth and Mars. Between Nov. 28 and Dec. 13, Mars and the sun will be within two degrees of each other as seen from Earth, blocking radio transmission between the spacecraft and Earth. During that time, no commands will be sent to Phoenix, but daily downlinks from Phoenix will continue through NASA's Odyssey and Mars Reconnaissance orbiters. At this time, controllers can't predict whether the fourth heater would be disabled before or after conjunction.

The Phoenix mission is led by Peter Smith of the University of Arizona, Tucson, with project management at the Jet Propulsion Laboratory and development partnership at Lockheed Martin, Denver. International contributions come from the Canadian Space Agency; the University of Neuchatel, Switzerland; the universities of Copenhagen and Aarhus in Denmark; the Max Planck Institute in Germany; and the Finnish Meteorological Institute. The California Institute of Technology in Pasadena manages JPL for NASA.

NASA Orbiter Reveals Details of a Wetter Mars

NASA's Mars Reconnaissance Orbiter has observed a new category of minerals spread across large regions of Mars. This discovery suggests that liquid water remained on the planet's surface a billion years later than scientists believed, and it played an important role in shaping the planet's surface and possibly hosting life.

Researchers examining data from the orbiter's Compact Reconnaissance Imaging Spectrometer for Mars have found evidence of hydrated silica, commonly known as opal. The hydrated, or water-containing, mineral deposits are telltale signs of where and when water was present on ancient Mars.

"This is an exciting discovery because it extends the time range for liquid water on Mars, and the places where it might have supported life," said Scott Murchie, the spectrometer's principal investigator at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "The identification of opaline silica tells us that water may have existed as recently as 2 billion years ago."

Until now, only two major groups of hydrated minerals, phyllosilicates and hydrated sulfates, had been observed by spacecraft orbiting Mars. Clay-like phyllosilicates formed more than 3.5 billion years ago where igneous rock came into long-term contact with water. During the next several hundred million years, until approximately 3 billion years ago, hydrated sulfates formed from the evaporation of salty and sometimes acidic water.

The newly discovered opaline silicates are the youngest of the three types of hydrated minerals. They formed where liquid water altered materials created by volcanic activity or meteorite impact on the Martian surface. One such location noted by scientists is the large Martian canyon system called Valles Marineris.

"We see numerous outcrops of opal-like minerals, commonly in thin layers extending for very long distances around the rim of Valles Marineris and sometimes within the canyon system itself," said Ralph Milliken of NASA's Jet Propulsion Laboratory in Pasadena, Calif.

Milliken is lead author of an article in the November issue of "Geology" that describes the identification of opaline silica. The study reveals that the minerals, which also were recently found in Gusev Crater by NASA's Mars rover Spirit, are widespread and occur in relatively young terrains.

In some locations, the orbiter's spectrometer observed opaline silica with iron sulfate minerals, either in or around dry river channels. This indicates the acidic water remained on the Martian surface for an extended period of time. Milliken and his colleagues believe that in these areas, low-temperature acidic water was involved in forming the opal. In areas where there is no clear evidence that the water was acidic, deposits may have formed under a wide range of conditions.

"What's important is that the longer liquid water existed on Mars, the longer the window during which Mars may have supported life," says Milliken. "The opaline silica deposits would be good places to explore to assess the potential for habitability on Mars, especially in these younger terrains."

The spectrometer collects 544 colors, or wavelengths, of reflected sunlight to detect minerals on the surface of Mars. Its highest resolution is about 20 times sharper than any previous look at the planet in near-infrared wavelengths.

NASA's Jet Propulsion Laboratory manages the Mars Reconnaissance Orbiter mission for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The Applied Physics Laboratory led the effort to build the spectrometer and operates the instrument in coordination with an international team of researchers from universities, government and the private sector.

More information about the Mars Reconnaissance Orbiter is at http://www.nasa.gov/mro

NASA Tests Rover Concepts in Arizona

NASA's newest lunar rover prototype has now gone farther than it ever has before.

A collection of engineers, astronauts and geologists have spent the past week testing out the Small Pressurized Rover in the 11th annual Desert RATS – or Research and Technology Studies -- field tests. Two teams of one astronaut and one geologist each have been driving the rover through the Arizona desert, trying it out in two different configurations.

One configuration leaves the crew members free to get on and off the rover whenever they like, but they must wear spacesuits at all times to protect them from the lunar environment. The second configuration -- called the Small Pressurized Rover, or SPR -- adds a module on top of the rover’s chassis that the crew can sit inside as they drive the vehicle, donning spacesuits whenever they want to get out.

For the first week of tests, the rover has been driven on day-long trips to determine how each configuration performed. These have been some of the longest drives the prototype has ever made, but next week the group will step it up another notch or two, by going on a three-day drive through the desert in the SPR to determine how it performs and whether it's comfortable enough for long-duration trips.

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Closest Planetary System Hosts Two Asteroid Belts

New observations from NASA's Spitzer Space Telescope indicate that the nearest planetary system to our own has two asteroid belts. Our own solar system has just one.

The star at the center of the nearby system, called Epsilon Eridani, is a younger, slightly cooler and fainter version of the sun. Previously, astronomers had uncovered evidence for two possible planets in the system, and for a broad, outer ring of icy comets similar to our own Kuiper Belt.

Now, Spitzer has discovered that the system also has dual asteroid belts. One sits at approximately the same position as the one in our solar system. The second, denser belt, most likely also populated by asteroids, lies between the first belt and the comet ring. The presence of the asteroid belts implies additional planets in the Epsilon Eridani system.

"This system probably looks a lot like ours did when life first took root on Earth," said Dana Backman, an astronomer at the SETI Institute, in Mountain View, Calif., and outreach director for NASA's Sofia mission. "The main difference we know of so far is that it has an additional ring of leftover planet construction material." Backman is lead author of a paper about the findings to appear Jan. 10 in the Astrophysical Journal.

Asteroid belts are rocky and metallic debris left over from the early stages of planet formation. Their presence around other stars signals that rocky planets like Earth could be orbiting in the system's inner regions, with massive gas planets circling near the belts' rims. In our own solar system, for example, there is evidence that Jupiter, which lies just beyond our asteroid belt, caused the asteroid belt to form long ago by stirring up material that would have otherwise coalesced into a planet. Nowadays, Jupiter helps keep our asteroid belt confined to a ring.

Astronomers have detected stars with signs of multiple belts of material before, but Epsilon Eridani is closer to Earth and more like our sun overall. It is 10 light-years away, slightly less massive than the sun, and roughly 800 million years old, or one-fifth the age of the sun.

Because the star is so close and similar to the sun, it is a popular locale in science fiction. The television series Star Trek and Babylon 5 referenced Epsilon Eridani, and it has been featured in novels by Issac Asimov and Frank Herbert, among others.

The popular star was also one of the first to be searched for signs of advanced alien civilizations using radio telescopes in 1960. At that time, astronomers did not know of the star's young age.

Spitzer observed Epsilon Eridani with both of its infrared cameras and its infrared spectrometer. When asteroid and comets collide or evaporate, they release tiny particles of dust that give off heat, which Spitzer can see. "Because the system is so close to us, Spitzer can really pick out details in the dust, giving us a good look at the system's architecture," said co-author Karl Stapelfeldt of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

The asteroid belts detected by Spitzer orbit at distances of approximately 3 and 20 astronomical units from the star (an astronomical unit is the average distance between Earth and the sun). For reference, our own asteroid belt lies at about 3 astronomical units from the sun, and Uranus is roughly 19 astronomical units away.

One of the two possible planets previously identified around Epsilon Eridani, called Epsilon Eridani b, was discovered in 2000. The planet is thought to orbit at an average distance of 3.4 astronomical units from the star -- just outside the innermost asteroid belt identified by Spitzer. This is the first time that an asteroid belt and a planet beyond our solar system have been found in a similar arrangement as our asteroid belt and Jupiter.

Some researchers had reported that Epsilon Eridani b orbits in an exaggerated ellipse ranging between 1 and 5 astronomical units, but this means the planet would cross, and quickly disrupt, the newfound asteroid belt. Instead, Backman and colleagues argue that this planet must have a more circular orbit that keeps it just outside the belt.

The other candidate planet was first proposed in 1998 to explain lumpiness observed in the star's outer comet ring. It is thought to lie near the inner edge of the ring, which orbits between 35 and 90 astronomical units from Epsilon Eridani.

The intermediate belt detected by Spitzer suggests that a third planet could be responsible for creating and shepherding its material. This planet would orbit at approximately 20 astronomical units and lie between the other two planets. "Detailed studies of the dust belts in other planetary systems are telling us a great deal about their complex structure," said Michael Werner, co-author of the study and project scientist for Spitzer at JPL. "It seems that no two planetary systems are alike."

JPL manages the Spitzer mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. More information about Spitzer is at http://www.spitzer.caltech.edu/spitzer and http://www.nasa.gov/spitzer . More information about extrasolar planets and NASA's planet-finding program is at http://planetquest.jpl.nasa.gov .

POTENT GREENHOUSE GAS MORE COMMON IN ATMOSPHERE THAN ESTIMATED

New research indicates a powerful greenhouse gas is at least four times more prevalent in the atmosphere than previously estimated. The research, based on data from a NASA-funded measurement network, examined nitrogen trifluoride, which is thousands of times more effective at warming the atmosphere than an equal mass of carbon dioxide.

Using new analytical techniques, Ray Weiss of the Scripps Institution of Oceanography in La Jolla, Calif., led a team of researchers in making the first atmospheric measurements of nitrogen trifluoride. The amount of the gas in the atmosphere, which could not be detected using previous techniques, had been estimated at less than 1,200 metric tons in 2006. The new research shows the actual amount was 4,200 metric tons. In 2008, about 5,400 metric tons of the gas are in the atmosphere, a quantity that is increasing at a rate of about 11 percent per year.

"Accurately measuring small amounts of nitrogen trifluoride in air has proven to be a very difficult experimental problem, and we are very pleased to have succeeded in this effort," Weiss said. The research will be published Oct. 31 in the American Geophysical Union's Geophysical Research Letters.

Emissions of nitrogen trifluoride were thought to be so low that the gas was not considered a significant potential contributor to global warming. It was not covered by the Kyoto Protocol, the 1997 agreement to reduce greenhouse gas emissions signed by 182 countries. The gas is 17,000 times more potent as a global warming agent than a similar mass of carbon dioxide. It survives in the atmosphere about five times longer than carbon dioxide. However, current nitrogen trifluoride emissions contribute only about 0.15 percent of the total global warming effect caused by current human-produced carbon dioxide emissions.

Nitrogen trifluoride is one of several gases used during the manufacture of liquid crystal flat-panel displays, thin-film solar cells and microcircuits. Many industries have used the gas in recent years as an alternative to perfluorocarbons, which also are potent greenhouse gases, because it was believed that no more than two percent of the nitrogen trifluoride used in these processes escaped into the atmosphere.

The Scripps team analyzed air samples gathered during the past 30 years, including samples from the NASA-funded Advanced Global Atmospheric Gases Experiment network of ground-based space stations. The network was created in the 1970s in response to international concerns about chemicals depleting the ozone layer. It is supported by NASA as part of its congressional mandate to monitor ozone-depleting trace gases, many of which also are greenhouse gases. Air samples are collected at several stations around the world. The Scripps team analyzed samples from coastal clean-air stations in California and Tasmania for this research.

The researchers found concentrations of the gas rose from about 0.02 parts per trillion in 1978 to 0.454 parts per trillion in 2008. The samples also showed significantly higher concentrations of nitrogen trifluoride in the Northern Hemisphere than in the Southern Hemisphere, which the researchers said is consistent with its use predominantly in that hemisphere. The current observed rate of increase of nitrogen trifluoride in the atmosphere corresponds to emissions of about 16 percent of the amount of the gas produced globally.

In response to the growing use of the gas and concerns that its emissions are not well known, Space Station Scientists recently have recommended adding it to the list of greenhouse gases regulated by Kyoto.

"As is often the case in studying atmospheric emissions, this study shows a significant disagreement between 'bottom-up' emissions estimates and the actual emissions as determined by measuring their accumulation in the atmosphere," Weiss said.

For more information about NASA and agency programs, visit:

http://www.nasa.gov

Next Moon Mission Begins Thermal Vacuum Test

NASA's Lunar Reconnaissance Orbiter, or LRO, has begun environmental testing in a thermal vacuum that simulates the harsh rigors of space.

The spacecraft, built at NASA's Goddard Space Flight Center in Greenbelt, Md., has been lifted into a four-story thermal vacuum chamber there for a test that will last approximately five weeks. Once sealed in the chamber, the satellite will undergo a series of tests that simulate the space environment it will encounter when it orbits the moon.

During the tests, NASA engineers will operate the spacecraft to ensure it is performing as planned. The project also will conduct mission simulations to further train and develop the team that will operate the spacecraft.

"This is an exciting time for our project" said Cathy Peddie, LRO deputy project manager at Goddard. "Thermal vacuum testing is one of our major milestones. Not only are we checking out LRO in a test facility that most closely matches its final destination, but we are getting more 'hands-on' time operating LRO as we will see it next year at the moon."

The orbiter will carry seven instruments to provide scientists with detailed maps of the lunar surface and enhance our understanding of the moon's topography, lighting conditions, mineralogical composition and natural resources. Information gleaned from LRO will be used to select safe landing sites, determine locations for future lunar outposts and help to mitigate radiation dangers to astronauts.

The orbiter will be shipped to NASA's Kennedy Space Center in Florida early next year to be prepared for its April 24 launch aboard an Atlas V rocket. Accompanying the spacecraft will be the Lunar Crater Observation and Sensing Satellite, a mission that will impact the moon's surface in its search for water ice.

Expedition 17 Crew Lands in Kazakhstan

Commander Sergei Volkov and Flight Engineer Oleg Kononenko of the 17th International Space Station crew landed on the steppes of Kazakhstan at 11:37 p.m. EDT Thursday after more than six months days in space.

All three people aboard the Soyuz TMA-12 spacecraft were reported to be in good condition after their re-entry and landing.

A Russian recovery team and NASA personnel reached the landing site by helicopter shortly after the Soyuz touched down. They helped the crew members into reclining chairs for medical tests and set up a medical tent nearby.

With Volkov and Kononenko was spaceflight participant Richard Garriott. He launched to the station Oct. 12 with the Expedition 18 crew, Commander Mike Fincke and Flight Engineer Yury Lonchakov, under contract with the Russian Federal Space Agency.

Astronaut Gregory Chamitoff came to the station aboard Discovery on its STS-124 mission, launched May 31. He served for the last part of Expedition 17 as a flight engineer. He remains aboard the station as a member of the Expedition 18 crew.
Expedition 17 crew members undocked their Soyuz spacecraft from the station at 8:16 p.m. Thursday. The deorbit burn to slow the Soyuz and begin its descent toward the Earth took place at 10:45 a.m.

When they landed, Volkov and Kononenko had spent 199 days in space on their Expedition 17 flight, 197 of them on the station.

Volkov, 35, a lieutenant in the Russian air force, returned from his first spaceflight. Kononenko, a spacecraft design engineer, also completed his first spaceflight.

+ Read more about Expedition 18
+ Read more about Expedition 17 + View crew timelines
+ View crew timelines

NASA's Phoenix Mars Team Wins National Space Club Award

The National Space Club presented NASA's Phoenix Mars Lander mission team with its Astronautics Engineer Award last night in Huntsville, Ala. Phoenix Project Manager Barry Goldstein of NASA's Jet Propulsion Laboratory, Pasadena, Calif., accepted the award on behalf of the team at the Space Club's 20th Annual Dr. Wernher von Braun Memorial Dinner.

The nonprofit National Space Club established the Astronautics Engineer Award in 1991. It is given to scientists and engineers in the United States who have led and made significant contributions in rocketry and astronautics. Past recipients include NASA's Return to Flight Team and Alan Stern, former associate administrator for NASA's Science Mission Directorate.

The dinner honors the memory of von Braun, the first director of NASA's Marshall Space Flight Center and one of the most important rocket developers and champions of space exploration in the 20th century.

"This award recognizes that our team really met the ideals of the von Braun legacy," said Goldstein. "Being recognized at a ceremony named for one of the seminal engineers in our industry is a true honor for our teams at JPL, Lockheed Martin, the University of Arizona, and the many other organizations responsible for our success."

The Phoenix Mars Lander reached the northern plains of Mars on May 25, 2008. The lander has been studying the Martian arctic for evidence of past liquid water and habitability. It is also learning about the Red Planet's current climate and atmosphere. Robotic laboratory instruments have sniffed, baked and tasted the Martian soil and ice for their chemical and mineral properties. Phoenix's cameras have returned more than 25,000 images of Mars.

Earlier this month, the Phoenix mission received a 2008 Popular Mechanics Breakthrough Award for innovation. In November, Phoenix will also be presented the 2008 Civil Space Award from the California Space Authority. The mission previously received the 2007 Arizona Governor's Innovation Award in the academia category.

The Astronautics Engineer award was one of five presented at the Space Club event. The other four awards are the Aerospace Educator Award, the Media Award, the Community Service Award, and the Dr. Wernher von Braun Space Flight Trophy. The Space Club's Huntsville chapter sponsored the event, which was held at the Davidson Center for Space Exploration.

The Phoenix mission is led by Principal Investigator Peter Smith of the University of Arizona, with project management at the Jet Propulsion Laboratory and development partnership at Lockheed Martin, located in Denver. International contributions come from the Canadian Space Agency; the University of Neuchatel; the universities of Copenhagen and Aarhus, Denmark; Max Planck Institute, Germany; and the Finnish Meteorological Institute.

NEXT HUBBLE TELESCOPE MEDIA TELECONFERENCE THURSDAY, OCT. 23

NASA will provide an update to reporters on the current efforts to restore Hubble Space Telescope science observations during a media teleconference on Thursday, Oct. 23, at 2 p.m. EDT.

The briefing participants are:
- Jon Morse, director of the Astrophysics Division in the Science Mission Directorate at NASA Headquarters in Washington
- Art Whipple, manager of the Hubble Systems Management Office at NASA's Goddard Space Flight Center in Greenbelt, Md.

To participate in the conference, reporters in the U.S. should call 1-888-469-0494 and use the pass code "Hubble." International reporters should call 1-415-228-3905.

A recorded replay of the teleconference will be available approximately one hour after the conclusion of the call by dialing 1-888-566-0499. International callers can hear the replay by calling 1-203-369-3057.

Audio of the teleconference will be streamed live at:

http://www.nasa.gov/newsaudio

NASA AND THE CHALLENGER CENTER ANNOUNCE NAMING CONTEST

NASA and the Challenger Center for Space Education have partnered to engage students in ongoing activities for one of NASA's concepts for astronaut housing on the moon through a contest to name a habitat in Antarctica. NASA currently is conducting a test of a lightweight, durable, inflatable habitat on the cold, harsh landscape of the National Science Foundation's McMurdo Station.

The Challenger Center is organizing and conducting the "Name that Habitat" competition for students in kindergarten through twelfth grades from Oct 21 to Nov. 20, 2008. The Challenger Center will recruit subject matter experts to serve as judges for the contest and will provide prizes and other items for the winner and participants. The winning name will be selected later this year and announced by scientists in Antarctica in January 2009. Student, teachers and the public will be able to follow the progress of inflatable habitat activities throughout the project.

The habitat was funded through NASA's Innovative Partnership Program's Seed Fund initiative, with in-kind resource contributions by the National Science Foundation and ILC Dover of Frederica, Del., the manufacturer of the structure. An inflatable habitat is one of several concepts being considered for astronaut housing on the moon.

The structure looks something like an inflatable backyard bounce house for children, but it is far more sophisticated. It is insulated, heated and is pressurized, and has power. It offers 384 square feet of living space and has, at its highest point, an 8-foot ceiling. During the test period, sensors will allow engineers to monitor the habitat's performance.

The contest helps NASA fulfill its mission to promote an interest in science, technology, engineering and mathematics education. The Challenger Center is an international, nonprofit educational organization founded in 1986 by the families of the astronauts lost during the last flight of the space shuttle Challenger. The goal of the organization is to foster student interest in careers in science, technology, engineering and mathematics.

For more information about entering the Name that Habitat contest, visit:

http://www.challenger.org/hab

The inflatable habitat is being developed under NASA's Innovative Partnerships Program. For more information about the program, visit:

http://www.ipp.nasa.gov

For more information about NASA and agency programs, visit:

http://www.nasa.gov

NASA INVITES REPORTERS TO TESTS OF MOON TOOLS IN HAWAII NOV. 13

Media are invited to observe tests of NASA equipment and rover concepts that will demonstrate how astronauts might prospect for lunar resources and make their own oxygen for survival on the moon. The tests will take place Thursday, Nov. 13, starting at 9 a.m. HST outside Hilo, Hawaii.

NASA's In Situ Resource Utilization project focuses on developing methods for astronauts to take advantage of lunar resources at landing sites on the moon. During two weeks of field tests, NASA will demonstrate prototype systems that could enable a sustainable and affordable lunar outpost by minimizing the amount of water and oxygen that must be supplied from Earth. The Pacific International Center for Exploration Systems, or PISCES, headquartered at the University of Hawaii, Hilo, will host the tests.

Reporters will be able to observe and photograph various tests of a prototype moon rover designed to prospect for ice in lunar craters, and two systems to manufacture oxygen from the lunar soil. Engineers involved in the development of these systems will be available for interviews.

Reporters must contact Kimberly Land at 757-746-4749, or Grey Hautaluoma at 202-358-0668 by Friday, Oct. 31, to R.S.V.P. to attend the event. Access to the test site is restricted and requires a letter of assignment on company letterhead for credentials.

For more information about NASA's plans to return to the moon, visit:

http://www.nasa.gov/exploration

For more information about PISCES, visit:

http://www.pisces.uhh.hawaii.edu

Phoenix Lander Finishes Soil Delivery to Onboard Labs

NASA's Phoenix Mars Lander has finished scooping soil samples to deliver to its onboard laboratories, and is now preparing to analyze samples already obtained. Scientists are anxious to analyze the samples as the power Phoenix generates continues to drop. The amount of sunlight is waning on Mars' northern plains as late-summer turns to fall.

The spacecraft's robotic arm is digging into the lower portion of the "Upper Cupboard" and "Stone Soup" areas of the Phoenix worksite. Its Surface Stereoscopic Imager is taking photos of this trenching so scientists can better map out the geology of the Red Planet's ice table.

"We're basically trying to understand the depth and extent of the ice table to tie together how geology and climate control its formation," said Phoenix mission scientist Diana Blaney of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Later this week, Phoenix engineers and scientists will use the robotic arm to attempt to push a soil sample piled in a funnel on top of the lander's Wet Chemistry Laboratory into a cell for analysis. They will take images of soil captured in its Optical Microscope, as well as take digital-elevation models of a rock called "Sandman" with Phoenix's Robotic Arm Camera.

Phoenix has operated nearly five months on Mars since landing on May 25, 2008.

NASA's Phoenix mission is led by Principal Investigator Peter Smith of the University of Arizona, Tucson, with project management at JPL, and development partnership at Lockheed Martin, Denver. International contributions come from the Canadian Space Agency; the University of Neuchatel; the universities of Copenhagen and Aarhus, Denmark; the Max Planck Institute, Germany; and the Finnish Meteorological Institute.

Scientists Seek Climate Clues From Atop Hawaiian Volcano

JPL scientists, satellites and ground-based instruments are contributing to a month-long, university-led experiment on Hawaii's Mauna Loa volcano to track water vapor in Earth's sub-tropics, which affects global temperatures, and rainfall in North America.

For the full story, go to the University of Colorado release at http://www.colorado.edu/news/reports/watervapor/

Climate change seeps into the sea

The ocean has helped slow global warming by absorbing much of the excess heat and heat-trapping carbon dioxide that has been going into the atmosphere since the start of the Industrial Revolution.

All that extra carbon dioxide, however, has been a bitter pill for the ocean to swallow. It's changing the chemistry of seawater, making it more acidic and otherwise inhospitable, threatening many important marine organisms.

Scientists call ocean acidification "the other carbon dioxide problem." They warn that because it causes such fundamental changes in the ocean, it could impact millions of people who depend on the ocean for food and resources. "The growing amount of carbon dioxide in the ocean could have a bigger effect on life on Earth than carbon dioxide in the atmosphere," says JPL's Charles Miller, deputy principal investigator for NASA's new Orbiting Carbon Observatory, scheduled to launch next January.

The ocean takes in and stores most of the heat from the sun that is deposited at Earth's surface -- heat that would otherwise be melting land ice and warming the atmosphere. The ocean also absorbs about one third of the carbon dioxide that humans now put into the air. The rest is taken up by terrestrial vegetation and soils or remains in the atmosphere, increasing the greenhouse effect.

"The ocean surface acts like a sponge to soak up excess carbon dioxide from the atmosphere," says Scott Doney, a senior scientist in marine chemistry at the Woods Hole Oceanographic Institution in Woods Hole, Mass. Much of the extra dissolved carbon is in the ocean’s upper few thousand feet. However, at high latitudes, surface water quickly cools, becomes saltier and denser and sinks, carrying the dissolved carbon to some of the deepest parts of the ocean.

Mix carbon dioxide with water and the result is carbonic acid. After that first simple chemical reaction comes a slightly more complicated series of changes in seawater chemistry. The final outcome is a lowering of the ocean's pH -- meaning the ocean is more acidic, and, ironically, a reduction in a particular form of carbon -- carbonate ion -- that many marine organisms need to make shells and skeletal material. The lower pH and lack of carbonate ion have serious consequences for life in the ocean.

Carbon, carbon everywhere, but not the right kind to use

Closest to the atmospheric source of excess carbon dioxide, the ocean’s surface waters are the first to show the effects of acidification. Since the beginning of the industrial era, the pH of surface waters has decreased slightly but significantly from 8.2 to 8.1, and it continues to decrease. Scientists project the pH of surface water will decrease by the year 2100 to a level not seen on Earth over the past 20 million years, if not longer.

Likely casualties of ocean acidification are the marine plants and animals that use carbonate to form hard shells or other structures. These include mollusks like clams and oysters, and reef-building corals. Not only does ocean acidification limit their access to the carbonate they need for building material, it could become severe enough to dissolve existing coral structures and the shells of living organisms.

Since most corals live in shallow waters, coral reefs, some of the most biologically diverse places on Earth, are particularly vulnerable. "They are already under assault from warming water, over-fishing and habitat degradation," says Doney. "Environmental stress is leading to more incidents of 'coral bleaching,' which occurs when the symbiotic algae that lives inside the coral leaves or dies, and from which reefs often do not recover. Ocean acidification may push corals over the edge."

Other sensitive areas are the Southern Ocean and the subpolar North Pacific, where acidification threatens to unravel important food chains by making life difficult for a small marine snail called a pteropod. It’s a favorite food of small fishes, which, in turn, support larger fishes, penguins, whales and seabirds. Ocean acidification strips seawater of the carbonate ion that pteropods need to build new shells, and it also damages their existing ones.

There will be some winners and losers, says Doney, as the effects of growing ocean acidification are felt. "Although we don’t know exactly how many species depend on pteropods, clams, oysters, mussels or other shelled organisms for food, or on coral reefs for critical habitat, it’s clear that ocean acidification will cause a wholesale alteration of some marine ecosystems in ways we can’t predict," he explains.

History isn't much of a guide. While there have been times in Earth's past when the ocean was more acidic than now, most environmental changes occurred at a considerably slower pace than today. "At the rates of climate change and ocean acidification we’re seeing now, many organisms may be not able to keep up," Doney says.

That sinking feeling

Much of the carbon now in the air will find its way into the ocean with predictable results. "Even if we stopped adding carbon dioxide to the atmosphere today, ocean acidification will continue to increase," says Doney. "What marine fisheries and coral reefs will look like 100 years from now is a big question. We need to know how much carbon dioxide is being taken up, more about the gas exchange between the ocean and the atmosphere, and how this mechanism is affected by climate change."

NASA’s new Orbiting Carbon Observatory will help provide some of the answers after it is launched in January 2009. A NASA Earth System Science Pathfinder mission, it will make precise measurements of atmospheric carbon dioxide on a global scale.

The Orbiting Carbon Observatory will help identify carbon dioxide sources and sinks -- things that absorb and store carbon -- on land and in the ocean and show how they vary over time. Researchers will be able to combine mission data with numerical models to estimate global patterns of the exchange of carbon dioxide from the ocean and atmosphere.

"We’ll have a much better idea about what’s going on over the ocean where measurements have been sparse," explains Miller. "This is especially true in the Southern Ocean, which we believe is a big sink for carbon dioxide based on existing models."

While the Orbiting Carbon Observatory may be the newest NASA mission to help address the issue of ocean acidification, NASA has many other projects and missions that provide important information about ocean biology and chemistry that relates directly to this problem. These include NASA's Moderate Resolution Imaging Spectroradiometer (MODIS), flying on the Terra and Aqua satellites, and the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS). These instruments collect data on ocean color -- a key component of many studies of ocean ecology, plankton and coral reefs. Another example is the recent National Oceanic and Atmospheric Administration and NASA-sponsored Southern Gas Exchange Experiment. During this six-week research cruise, scientists investigated how gases, including carbon dioxide, move between the ocean and the atmosphere in high winds and rough seas.

The really big question is how much longer the ocean can continue to be a sink for atmospheric carbon dioxide before becoming saturated -- a process that may already be underway. The implications for our future climate -- and the ocean -- are immense.

For more information Visit..

http://climate.jpl.nasa.gov/news/index.cfm?FuseAction=ShowNews&NewsID=26