Wednesday, December 29, 2010

Cassini Celebrates 10 Years Since Jupiter Encounter

0 comments

Ten years ago, on Dec. 30, 2000, NASA's Cassini spacecraft made its closest approach to Jupiter on its way to orbiting Saturn. The main purpose was to use the gravity of the largest planet in our solar system to slingshot Cassini towards Saturn, its ultimate destination. But the encounter with Jupiter, Saturn's gas-giant big brother, also gave the Cassini project a perfect lab for testing its instruments and evaluating its operations plans for its tour of the ringed planet, which began in 2004.

"The Jupiter flyby allowed the Cassini spacecraft to stretch its wings, rehearsing for its prime time show, orbiting Saturn," said Linda Spilker, Cassini project scientist based at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Ten years later, findings from the Jupiter flyby still continue to shape our understanding of similar processes in the Saturn system."

Cassini spent about six months - from October 2000 to March 2001 - exploring the Jupiter system. The closest approach brought Cassini to within about 9.7 million kilometers (6 million miles) of Jupiter's cloud tops at 2:05 a.m. Pacific Time, or 10:05 a.m. UTC, on Dec. 30, 2000.

Cassini captured some 26,000 images of Jupiter and its moons over six months of continual viewing, creating the most detailed global portrait of Jupiter yet.

While Cassini's images of Jupiter did not have higher resolution than the best from NASA's Voyager mission during its two 1979 flybys, Cassini's cameras had a wider color spectrum than those aboard Voyager, capturing wavelengths of radiation that could probe different heights in Jupiter's atmosphere. The images enabled scientists to watch convective lightning storms evolve over time and helped them understand the heights and composition of these storms and the many clouds, hazes and other types of storms that blanket Jupiter.

The Cassini images also revealed a never-before-seen large, dark oval around 60 degrees north latitude that rivaled Jupiter's Great Red Spot in size. Like the Great Red Spot, the large oval was a giant storm on Jupiter. But, unlike the Great Red Spot, which has been stable for hundreds of years, the large oval showed itself to be quite transient, growing, moving sideways, developing a bright inner core, rotating and thinning over six months. The oval was at high altitude and high latitude, so scientists think the oval may have been associated with Jupiter's powerful auroras.

The imaging team was also able to amass 70-day movies of storms forming, merging and moving near Jupiter's north pole. They showed how larger storms gained energy from swallowing smaller storms, the way big fish eat small fish. The movies also showed how the ordered flow of the eastward and westward jet streams in low latitudes gives way to a more disordered flow at high latitudes.

Meanwhile, Cassini's composite infrared spectrometer was able to do the first thorough mapping of Jupiter's temperature and atmospheric composition. The temperature maps enabled winds to be determined above the cloud tops, so scientists no longer had to rely on tracking features to measure winds. The spectrometer data showed the unexpected presence of an intense equatorial eastward jet (roughly 140 meters per second, or 310 mph) high in the stratosphere, about 100 kilometers (60 miles) above the visible clouds. Data from this instrument also led to the highest-resolution map so far of acetylene on Jupiter and the first detection of organic methyl radical and diacetylene in the auroral hot spots near Jupiter's north and south poles. These molecules are important to understanding the chemical interactions between sunlight and molecules in Jupiter's stratosphere.

As Cassini approached Jupiter, its radio and plasma wave instrument also recorded naturally occurring chirps created by electrons coming from a cosmic sonic boom. The boom occurs when supersonic solar wind - charged particles that fly off the sun - is slowed and deflected around the magnetic bubble surrounding Jupiter.

Because Cassini arrived at Jupiter while NASA's Galileo spacecraft was still orbiting the planet, scientists were also able to take advantage of near-simultaneous measurements from two different spacecraft. This coincidence enabled scientists to make giant strides in understanding the interaction of the solar wind with Jupiter. Cassini and Galileo provided the first two-point measurement of the boundary of Jupiter's magnetic bubble and showed that it was in the act of contracting as a region of higher solar wind pressure blew on it.

"The Jupiter flyby benefited us in two ways, one being the unique science data we collected and the other the knowledge we gained about how to effectively operate this complex machine," said Bob Mitchell, Cassini program manager based at JPL. "Today, 10 years later, our operations are still heavily influenced by that experience and it is serving us very well."

In celebrating the anniversary of Cassini's visit 10 years ago, scientists are also excited about the upcoming and proposed missions to the Jupiter system, including NASA's Juno spacecraft, to be launched next August, and the Europa Jupiter System Mission, which has been given a priority by NASA.

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, Calif., manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute in Boulder, Colo. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md., where the instrument was built. The radio and plasma wave science team is based at the University of Iowa, Iowa City, where the instrument was built.

Tuesday, December 28, 2010

Hole Punch Clouds over West Virginia

0 comments
Looking up on a chilly December morning in 2009, residents of rural West Virginia (southwest of Charleston) would have seen a halo of light bursting through the thin bank of clouds that hung overhead. The light was streaming through hole-punch clouds and canals, most likely created by passing airplanes. This image, taken by the Landsat-5 satellite on December 11, 2009, shows the unique conditions in which such holes form.

When airplanes, particularly propeller aircraft, pass through the clouds, they disturb the air. The air expands in the turbulence created by the propellers and wings. As the air expands, it cools, and the supercooled water droplets in the clouds freeze into ice. These ice crystals act as seeds for other water droplets to freeze onto. Over time, the water clouds around the disturbed area disappear and an ice cloud grows.

The clouds created in this manner take two different forms: hole-punch clouds and canals. The hole-punch clouds consist of an ice cloud surrounded by a halo of clear sky where the water in the clouds has frozen into ice and disappeared. Canals resemble contrails. They are long streaks where ice clouds are continuously being formed as the aircraft travels in the altocumulus cloud layer.

The image above was made with both infrared and visible light, in a combination that makes it possible to distinguish between water and ice clouds. The even cloud blanket is pale blue and pink, the warmer tones of water clouds. In the hole-punch clouds, however, we see the iridescent blue signature of ice, surrounded by a halo of clear sky. A similar blue streak from a canal runs across the top left.

The surrounding cloud bank is made up of altocumulus clouds, sitting at an altitude of 2,000 to 7,000 meters (6,600 – 23,000 feet), where temperatures ranged between minus five and minus twenty degrees Celsius, according to radiosonde data taken nearby. Despite the chill, this image reveals that the clouds were made of water, not ice.

For more information visit http://earthobservatory.nasa.gov/IOTD/view.php?id=48100

Monday, December 27, 2010

Cities at Night, Northern China

0 comments
Nighttime images have a way of dramatically revealing the amount of land development in metropolitan areas. This astronaut photograph features two of China’s most populous cities—Beijing and Tianjin—both in the northeastern part of the country near the Bohai Gulf. The United Nations estimated the 2010 population of the Beijing metropolitan area to be approximately 12 million, with the population of Tianjin estimated at more than 7 million.

The smaller city of Langfang, located midway between Beijing and Tianjin, is also clearly visible, as are several smaller developments to the northeast. The dark regions are mainly agricultural fields, with wheat and corn being the major crops.

Beijing (also known as Peking) is one of the ancient capital cities and the current capital of the People’s Republic of China. Its regular grid pattern is clearly visible at image upper left; concentric rings of major roadways around the city have been added as the metropolitan area has expanded. Tianjin is a major trade center linked to seaports on the Bohai Gulf. The city lies along the Grand Canal of China, a major artificial waterway extending southward for 1,176 kilometers (1,103 miles) from Beijing to Hangzhou.

This photograph was acquired by astronauts on the International Space Station (ISS) when it was located approximately 630 kilometers (391 miles) away, over the Yellow Sea near the western coastline of North Korea. The flattened perspective of the urban areas is the result of the viewing angle and distance from the ISS. The city light patterns are very clear, indicating that there was little cloud cover or haze in the region at the time.

For more information visit http://earthobservatory.nasa.gov/IOTD/view.php?id=48076&src=imgrss

Sunday, December 26, 2010

J-2X Turbomachinery Complete

0 comments

NASA and Pratt & Whitney Rocketdyne have successfully completed the heart of the J-2X upper stage rocket engine -- the turbomachinery assemblies -- for the first development engine off the production line.

The engine's turbomachinery consists of two turbopumps, each part pump and part turbine. Turbines provide the power to drive the pumps. One pump pushes high-pressure liquid oxygen, or oxidizer, and the other pumps liquid hydrogen fuel through the engine and to the engine's main injector. When the two meet, the fuels combine in a controlled high-pressure explosion producing the combustion needed to propel a launch vehicle to its journey to space.

"The turbopumps are extremely complicated engine components whose design requires delicate balances between many of the fields of mechanical engineering, and whose fabrication and assembly involve extremely precise construction," said Gary Genge, J-2X turbomachinery manager at NASA's Marshall Space Flight Center in Huntsville, Ala. "We're thrilled these parts are completed, and are ready to send to Stennis Space Center for assembly onto our first engine."

The J-2X engine is a highly efficient and versatile rocket engine and has the ideal thrust and performance characteristics to power the upper stage of a heavy-lift launch vehicle. Investments made in developing the J-2X engine provide the nation with a new, robust rocket engine for future human spaceflight missions to low-Earth orbit, Mars or an asteroid.

NASA’s Marshall Space Flight Center manages J-2X engine development. Pratt & Whitney Rocketdyne, Canoga Park, Calif., is the prime contractor.

For more information visit http://www.nasa.gov/mission_pages/j2x/10-171.html

Thursday, December 23, 2010

Opportunity Studying a Football-Field Size Crater

0 comments

On Dec. 16, 2010, NASA's Mars Exploration Rover Opportunity reached a crater about the size of a football field-some 90 meters (295 feet) in diameter. The rover team plans to use cameras and spectrometers during the next several weeks to examine rocks exposed at the crater, informally named "Santa Maria."

A mosaic of image frames taken by Opportunity's navigation camera on Dec. 16 shows the crater's sharp rim and rocks ejected from the impact that had excavated the crater.

Opportunity completed its three-month prime mission on Mars in April 2004 and has been working in bonus extended missions since then. After the investigations at Santa Maria, the rover team plans to resume a long-term trek by Opportunity to the rim of Endeavour Crater, which is about 22 kilometers (14 miles) in diameter.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-430#1

Wednesday, December 22, 2010

NASA's Next Mars Rover to Zap Rocks With Laser

0 comments
A rock-zapping laser instrument on NASA's next Mars rover has roots in a demonstration that Roger Wiens saw 13 years ago in a colleague's room at Los Alamos National Laboratory in New Mexico.

The Chemistry and Camera (ChemCam) instrument on the rover Curiosity can hit rocks with a laser powerful enough to excite a pinhead-size spot into a glowing, ionized gas. ChemCam then observes the flash through a telescope and analyzes the spectrum of light to identify the chemical elements in the target.

That information about rocks or patches of soil up to about 7 meters (23 feet) away will help the rover team survey the rover's surroundings and choose which targets to drill into, or scoop up, for additional analysis by other instruments on Curiosity. With the 10 science instruments on the rover, the team will assess whether any environments in the landing area have been favorable for microbial life and for preserving evidence about whether life existed. In late 2011, NASA will launch Curiosity and the other parts of the flight system, delivering the rover to the surface of Mars in August 2012.

Wiens, a geochemist with the U.S. Department of Energy's Los Alamos National Laboratory, serves as ChemCam's principal investigator. An American and French team that he leads proposed the instrument during NASA's 2004 open competition for participation in the Mars Science Laboratory project, whose rover has since been named Curiosity.

In 1997, while working on an idea for using lasers to investigate the moon, Wiens visited a chemistry laboratory building where a colleague, Dave Cremers, had been experimenting with a different laser technique. Cremers set up a cigar-size laser powered by a little 9-volt radio battery and pointed at a rock across the room.

"The room was well used. Every flat surface was covered with instruments, lenses or optical mounts," Wiens recalls. "The filing cabinets looked like they had a bad case of acne. I found out later that they were used for laser target practice."

Cremers pressed a button. An invisible beam from the laser set off a flash on a rock across the room. The flash was ionized gas, or plasma, generated by the energy from the laser exciting atoms in the rock. A spectrometer pointed at the glowing plasma recorded the intensity of light at different wavelengths for determining the rock's atomic ingredients.

Researchers have used lasers for inducing plasmas for decades. What impressed Wiens in this demonstration was the capability to do it with such a low-voltage power source and compact hardware. Using this technology for a robot on another planet seemed feasible. From that point, more than a decade of international development and testing resulted in ChemCam being installed on Curiosity in September 2010.

The international collaboration came about in 2001 when Wiens introduced a former Los Alamos post-doctoral researcher, Sylvestre Maurice, to the project. The core technology of ChemCam, laser-induced breakdown spectroscopy, had been used for years in France as well as in America, but it was still unknown to space scientists there. "The technique is both flashy and very compelling scientifically, and the reviewers in France really liked that combination," Maurice said. A French team was formed, and work on a new laser began.

"The trick is very short bursts of the laser," Wiens said. "You really dump a lot of energy onto a small spot -- megawatts per square millimeter -- but just for a few nanoseconds."

The pinhead-size spot hit by ChemCam's laser gets as much power focused on it as a million light bulbs, for five one-billionths of a second. Light from the resulting flash comes back to ChemCam through the instrument's telescope, mounted beside the laser high on the rover's camera mast. The telescope directs the light down an optical fiber to three spectrometers inside the rover. The spectrometers record intensity at 6,144 different wavelengths of ultraviolet, visible and infrared light. Different chemical elements in the target emit light at different wavelengths.

If the rock has a coating of dust or a weathered rind, multiple shots from the laser can remove those layers to provide a clear shot to the rock's interior composition. "We can see what the progression of composition looks like as we get a little bit deeper with each shot," Wiens said.

Earlier Mars rover missions have lacked a way to identify some of the lighter elements, such as carbon, oxygen, hydrogen, lithium and boron, which can be clues to past environmental conditions in which the rock was formed or altered. After NASA's Mars Exploration Rover Spirit examined an outcrop called "Comanche" in 2005, it took years of analyzing indirect evidence before the team could confidently infer the presence of carbon in the rock. A single observation with ChemCam could detect carbon directly.

ChemCam will be able to interrogate multiple targets the same day, gaining information for the rover team's careful selection of where to drill or scoop samples for laboratory investigations that will take multiple days per target. It can also check the composition of targets inaccessible to the rover's other instruments, such as rock faces beyond the reach of Curiosity's arm.

The instrument's telescope doubles as the optics for the camera part of ChemCam, which records images on a one-megapixel detector. The telescopic camera will show context of the spots hit with the laser and can also be used independently of the laser.

The French half of the ChemCam team, headed by Maurice and funded by France's national space agency, provided the instrument's laser and telescope. Maurice is a spectroscopy expert with the Centre d'Étude Spatiale des Rayonnements, in Toulouse, France. Los Alamos National Laboratory supplied the spectrometers and data processor inside the rover. The optical design of the spectrometers came from Ocean Optics, Dunedin, Fla.

The ChemCam team includes experts in mineralogy, geology, astrobiology and other fields, with some members also on other Curiosity instrument teams.

With the instrument now installed on Curiosity, testing continues at NASA's Jet Propulsion Laboratory, Pasadena, Calif. JPL, a division of the California Institute of Technology in Pasadena, is assembling the rover and other components of the Mars Science Laboratory flight system for launch from Florida between Nov. 25 and Dec. 18, 2011.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-428

Tuesday, December 21, 2010

Cassini Marks Holidays With Dramatic Views of Rhea

0 comments
Newly released for the holidays, images of Saturn's second largest moon Rhea obtained by NASA's Cassini spacecraft show dramatic views of fractures cutting through craters on the moon's surface, revealing a history of tectonic rumbling. The images are among the highest-resolution views ever obtained of Rhea.

"These recent, high-resolution Cassini images help us put Saturn's moon in the context of the moons' geological family tree," said Paul Helfenstein, Cassini imaging team associate, based at Cornell University, Ithaca, N.Y. "Since NASA's Voyager mission visited Saturn, scientists have thought of Rhea and Dione as close cousins, with some differences in size and density. The new images show us they're more like fraternal twins, where the resemblance is more than skin deep. This probably comes from their nearness to each other in orbit."

Cassini scientists designed the March 2010 and November 2009 encounters in part to search for a ring thought to encircle the moon. During the March flyby, Cassini made its closest- approach to Rhea's surface so far, swooping within 100 kilometers (62 miles) of the moon. Based on these observations, however, scientists have since discounted the possibility that Rhea might currently have a faint ring above its equator.

These flybys nonetheless yielded unique views of other features on the moon, including ones that are among the best ever obtained of the side of Rhea that always faces away from Saturn. Other views show a web of bright, "wispy" fractures resembling some that were first spotted on another part of Rhea by the two Voyager spacecraft in 1980 and 1981.

At that time, scientists thought the wispy markings on the trailing hemispheres – the sides of moons that face backward in the orbit around a planet – of Rhea and the neighboring moon Dione were possible cryovolcanic deposits, or the residue of icy material erupting. The low resolution of Voyager images prevented a closer inspection of these regions. Since July 2004, Cassini's imaging cameras have captured pictures the trailing hemispheres of both satellites several times at much higher resolution. The images have shown that the wispy markings are actually exposures of bright ice along the steep walls of long scarps, or lines of cliffs, that indicate tectonic activity produced the features rather than cryovolcanism.

Data collected by Cassini's imaging cameras in November 2009 showed the trailing hemisphere at unprecedented resolution. Scientists combined images taken about one hour apart to create a 3-D image of this terrain, revealing a set of closely spaced troughs that sometimes look linear and sometimes look sinuous. The 3-D image also shows uplifted blocks interspersed through the terrain that cut through older, densely cratered plains. While the densely cratered plains imply that Rhea has not experienced much internal activity since its early history that would have repaved the moon, these imaging data suggest that some regions have ruptured in response to tectonic stress more recently. Troughs and other fault topography cut through the two largest craters in the scene, which are not as scarred with smaller craters, indicating that these craters are comparatively young. In some places, material has moved downslope along the scarps and accumulated on the flatter floors.

A mosaic of the March flyby images shows bright, icy fractures cutting across the surface of the moon, sometimes at right angles to each other. A false-color view of the entire disk of the moon's Saturn-facing side reveals a slightly bluer area, likely related to different surface compositions or to different sizes and fine-scale textures of the grains making up the moon's icy soil.

The new images have also helped to enhance maps of Rhea, including the first cartographic atlas of features on the moon complete with names approved by the International Astronomical Union. Thanks to the recent mission extension, Cassini will continue to chart the terrain of this and other Saturnian moons with ever-improving resolution, especially for terrain at high northern latitudes, until 2017.

"The 11th of January 2011 will be especially exciting, when Cassini flies just 76 kilometers [47 miles] above the surface of Rhea," said Thomas Roatsch, a Cassini imaging team scientist based at the German Aerospace Center Institute of Planetary Research in Berlin. "These will be by far the best images we've ever had of Rhea's surface – details down to just a few meters will become recognizable."

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

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-424

Monday, December 20, 2010

Cassini Takes Close-Up of Enceladus Northern Hemisphere

0 comments
NASA's Cassini spacecraft will be making its close flyby of the northern hemisphere of Saturn's moon Enceladus today, Monday, Dec. 20. The closest approach will take place at 5:08 PM PST (8:08 EST) on Dec. 20, or 1:08 AM UTC on Dec. 21. The spacecraft will zip by at an altitude of about 48 kilometers (30 miles) above the icy moon's surface.

Cassini's fields and particles instruments will get priority during this flyby. They will be trying to characterize the particles that may form a tenuous atmosphere around Enceladus and see if they may be similar to the faint oxygen- and carbon-dioxide atmosphere detected recently around Rhea, another Saturnian moon. The instruments will be particularly interested in the Enceladus environment away from the jets emanating from the south polar region. A goal of the observations will be to try to measure the rate of dust coming off the moon from the bombardment of micrometeoroids alone. These measurements will help scientists understand the rate of micrometeoroid bombardment in the Saturn system, which will help them get at the age of Saturn's main rings.

The composite infrared spectrometer and imaging cameras will also be active, looking for additional hot spots on the moon and taking pictures of some regions at a higher resolution than is currently available.

This is the 13th flyby of Enceladus in Cassini's mission and takes a similar path to the last Enceladus flyby.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif. manages the mission for NASA's Science Mission Directorate, Washington, D.C.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-423

Sunday, December 19, 2010

Get Ready for the Solstice Lunar Eclipse!

0 comments
The first total lunar eclipse in two years will grace the sky the night of Monday, Dec. 20, and we want you to be there. Sure, it's a school night, but with winter solstice and a new year upon us, what better time to gather your family and friends to see the moon in a new light?

At NASA, we're pretty excited for this year's lunar eclipse, so we're offering a number of features and activities for astronomy buffs and moon-gazers alike. To learn about the science behind eclipses, visit NASA's Eclipse page, where Mr. Eclipse provides information about viewing the eclipse from all over the United States.

Want to know more about the lunar eclipse? Lunar experts from NASA's Marshall Space Flight Center will be hosting two live Web chats to discuss the eclipse. On Monday, Dec. 20 from 3-4 p.m. EST, Dr. Rob Suggs will answer your questions. Later on Dec. 20, make plans to stay "Up All Night" with astronomer Mitzi Adams at she answers your questions from midnight to 5:00 a.m. EST.

Starting now, you can subscribe to NASA JPL's "I'm There: Lunar Eclipse" text campaign to connect with others in your area by texting us your viewing location and comments on the night of the eclipse. To sign up, text IMTHERE to 67463 and we'll send you a reminder to go out and watch on Dec. 20 (message and data rates may apply).

Want to share or flip through photos of the eclipsed moon? Join NASA JPL's lunar eclipse Flickr group and connect with other professional and amateur photographers as they capture the moon's path through the Earth's shadow. We'll choose one lucky photographer to have his or her work featured as official JPL wallpaper at http://www.jpl.nasa.gov/wallpaper.

If you don't want to brave the December chill, or if your weather doesn't cooperate for lunar viewing, we have you covered! A live video feed of the lunar eclipse will be streamed online on Dec. 20. The camera is mounted at NASA's Marshall Space Flight Center in Huntsville, Ala.

On Dec. 20 and 21, join the conversation on Twitter by including #eclipse and @NASAJPL in your lunar eclipse tweets, and you may even see them show up among our live comment stream on NASA JPL's "I'm There: Lunar Eclipse" program.

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

Thursday, December 16, 2010

SORCE's Solar Spectral Surprise

0 comments
Two satellite instruments aboard NASA's Solar Radiation & Climate Experiment (SORCE) mission -- the Total Solar Irradiance Monitor (TIM) and the Solar Irradiance Monitor (SIM) -- have made daily measurements of the sun's brightness since 2003.

The two instruments are part of an ongoing effort to monitor variations in solar output that could affect Earth's climate. Both instruments measure aspects of the sun's irradiance, the intensity of the radiation striking the top of the atmosphere.

Instruments similar to TIM have made daily irradiance measurements of the entire solar spectrum for more than three decades, but the SIM instrument is the first to monitor the daily activity of certain parts of the spectrum, a measurement scientists call solar spectral irradiance.

In recent years, SIM has collected data that suggest the sun's brightness may vary in entirely unexpected ways. If the SIM's spectral irradiance measurements are validated and proven accurate over time, then certain parts of Earth’s atmosphere may receive surprisingly large doses of solar radiation even during lulls in solar activity.

"We have never had a reason until now to believe that parts of the spectrum may vary out of phase with the solar cycle, but now we have started to model that possibility because of the SIM results,” said Robert Cahalan, the project scientist for SORCE and the head of the climate and radiation branch at NASA's Goddard Space Flight Center in Greenbelt, Md.

Cahalan, as well as groups of scientists from the University of Colorado at Boulder and Johns Hopkins University, presented research at the American Geophysical Union meeting in San Francisco in December that explored the climate implications of the recent SIM measurements.

Cahalan’s modeling, for example, suggests that the sun may underlie variations in stratospheric temperature more strongly than currently thought. Measurements have shown that stratospheric temperatures vary by about 1 °C (1.8 °F) over the course of a solar cycle, and Cahalan has demonstrated that inputting SIM’s measurements of spectral irradiance into a climate model produces variations of that same magnitude.

Without inclusion of SIM data, the model produces stratospheric temperature variations only about a fifth as strong as would be needed to explain observed stratospheric temperature variations. “We may have a lot more to learn about how solar variability works, and how the sun might influence our climate," Cahalan said.

Measuring Variation

As recently as the 1970s, scientists assumed that the sun's irradiance was unchanging; the amount of energy it expels was even called the "solar constant." However, instruments similar to TIM and SIM have made clear that the sun's output actually fluctuates in sync with changes in the sun's magnetic field.

Indeed, TIM and its predecessor instruments, whose records of irradiance began in 1978, show that the sun's output varies by about 0.1 percent as the sun cycles through periods of high and low electromagnetic activity every eleven years or so. In practice, this cycling means the sun's brightness, as measured by TIM, goes up a bit when large numbers of sunspots and accompanying bright spots called faculae are present on the sun, yet goes down slightly when sunspots and faculae are sparse, like they have been in the last few years as the sun has gone through an unusually quiet period.

However, there is a critical difference between the SIM and TIM, explains Jerry Harder, the lead SIM instrument scientist and a researcher at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado in Boulder. While the TIM lumps all wavelengths -- including infrared, visible, and ultraviolet light -- into one overall measurement, the SIM isolates and monitors specific portions of the spectrum.

Notably, this makes SIM the first space-based instrument capable of continuously monitoring the visible and near-infrared portion, parts of the spectrum that are particularly important for the climate. SIM also offers the most comprehensive view of the individual components that make up the sun's total solar irradiance to date.

Some of the variations that SIM has measured in the last few years do not mesh with what most scientists expected. Climatologists have generally thought that the various part of the spectrum would vary in lockstep with changes in total solar irradiance.

However, SIM suggests that ultraviolet irradiance fell far more than expected between 2004 and 2007 -- by ten times as much as the total irradiance did -- while irradiance in certain visible and infrared wavelengths surprisingly increased, even as solar activity wound down overall.

The steep decrease in the ultraviolet, coupled with the increase in the visible and infrared, does even out to about the same total irradiance change as measured by the TIM during that period, according to the SIM measurements.

The stratosphere absorbs most of the shorter wavelengths of ultraviolet light, but some of the longest ultraviolet rays (UV-A), as well as much of the visible and infrared portions of the spectrum, directly heat Earth's lower atmosphere and can have a significant impact on the climate.

Climate Consequences?

Some climatologists, including Judith Lean of the United States Naval Research Laboratory, Washington, remain skeptical of the SORCE SIM measurements. "I strongly suspect the SIM trends are instrumental, not solar," said Lean, noting that instrumental drift has been present in every instrument that has tracked ultraviolet wavelengths to date.

"If these SIM measurements indicate real solar variations, then it would mean you could expect a warmer surface during periods of low solar activity, the opposite of what climate models currently assume," said Gavin Schmidt, a climate modeling specialist at NASA's Goddard Institute for Space Studies in New York City.

It would also imply that the sun's contribution to climate change over the last century or so might be even smaller than currently thought, suggesting that the human contribution to climate change may in turn be even larger than current estimates.

However, the surprising SIM measurements correspond with a period of unusually long and quiescent solar minimum that extended over 2007 to 2009. It may not be representative of past or future solar cycles, solar scientists caution.

Researchers will surely continue puzzling over the surprising SIM results for some time, but there is already considerable agreement on one point: that the need for continuous SIM and TIM measurements going forward has grown more urgent.

Modeling studies are showing that our climate depends critically on the true solar spectral variations. "If we don't have the instruments up there to watch this closely, we could be arguing about spectral irradiance and climate for decades," said Cahalan.

A new TIM instrument is slated to launch on the Glory satellite this February, but a replacement for the SORCE SIM instrument -- called the Total and Spectral Solar Irradiance Sensor (TSIS) -- likely won't fly until 2014 or 2015. This could create a gap between the current SIM and its replacement, a situation that would present a significant obstacle to identifying any possible longer-term trend in solar spectral irradiances, and thus to nailing down the sun’s role in long-term climate change.

"Both instruments -- TIM and SIM -- are absolutely critical for understanding how climate works. We neglect either of them at our peril," said Cahalan.

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

Contempo Technologies PVT Ltd Mission

0 comments
Life is best at Contempo technologies PVT LTD. People are very friendly and Contempo technologies organize many social events that help to know each other. All other companies rarely care about employee socialism. In Contempo tech that is not the case people are allowed to be friendly with each other in a pleasant office environment. Events like Christmas party, quiz, Halloween party makes people enjoy the company. Contempo technologies pvt ltd has a team that helps people get to know each other. At Contempo they never felt they never give stress like IT Company. Usually IT work is very stressful but in this company it has not been the case.

Please name one company that gives equal important to extracurricular activities and work. Here in Contempo technologies PVT ltd they do it they give the feeling that we need to be part of this world to work and enjoy. People here are not just money minded most companies are just money minded and never care what people think about the work environment. Other companies they just want us to work and leave the place in many cases till late nights but they never encourage us financially. All they want is work, work , work from us. But in Contempo technologies pvt ltd they don’t see it that way. The way they give important to fun activities it clearly portraits their feeling on what they want to give to an employee. Contempo technologies PVT LTd just don’t see work they utilize our other special skills too.

Wednesday, December 15, 2010

NASA's Odyssey Spacecraft Sets Exploration Record on Mars

0 comments

NASA's Mars Odyssey, which launched in 2001, will break the record Wednesday for longest-serving spacecraft at the Red Planet. The probe begins its 3,340th day in Martian orbit at 5:55 p.m. PST (8:55 p.m. EST) on Wednesday to break the record set by NASA's Mars Global Surveyor, which orbited Mars from 1997 to 2006.

Odyssey's longevity enables continued science, including the monitoring of seasonal changes on Mars from year to year and the most detailed maps ever made of most of the planet. In 2002, the spacecraft detected hydrogen just below the surface throughout Mars' high-latitude regions. The deduction that the hydrogen is in frozen water prompted NASA's Phoenix Mars Lander mission, which confirmed the theory in 2008. Odyssey also carried the first experiment sent to Mars specifically to prepare for human missions, and found radiation levels around the planet from solar flares and cosmic rays are two to three times higher than around Earth.

Odyssey also has served as a communication relay, handling most of the data sent home by Phoenix and NASA's Mars Exploration Rovers Spirit and Opportunity. Odyssey became the middle link for continuous observation of Martian weather by NASA's Mars Global Surveyor and NASA's Mars Reconnaissance Orbiter.

"Odyssey has proved itself to be a great spacecraft, but what really enables a spacecraft to reach this sort of accomplishment is the people behind it," said Gaylon McSmith, Odyssey project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "This is a tribute to the whole Odyssey team."

Odyssey will support the 2012 landing of the Mars Science Laboratory and surface operations of that mission. Mars Science Laboratory, also known as the Curiosity rover, will assess whether its landing area has had environmental conditions favorable for microbial life and preserving evidence about whether life has existed there. The rover will carry the largest, most advanced set of instruments for scientific studies ever sent to the Martian surface.

"The Mars program clearly demonstrates that world-class science coupled with sound and creative engineering equals success and longevity," said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington.

Other recent NASA spacecraft at Mars include the Mars Global Surveyor that began orbiting the Red Planet in 1997. The Spirit and Opportunity rovers landed on Mars in January 2004. They have been exploring for six years, far surpassing their original 90-day mission. Phoenix landed May 25, 2008, farther north than any previous spacecraft to the planet's surface. The mission's biggest surprise was the discovery of perchlorate, an oxidizing chemical on Earth that is food for some microbes, but potentially toxic for others. The solar-powered lander completed its three-month mission and kept working until sunlight waned two months later. MRO arrived at Mars in 2006 on a search for evidence that water persisted on the planet's surface for a long period of time.

Odyssey is managed by JPL for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems in Denver built the spacecraft. JPL and Lockheed Martin collaborate on operating the spacecraft.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-418

Tuesday, December 14, 2010

Hot Plasma Explosions Inflate Saturn's Magnetic Field

0 comments

A new analysis based on data from NASA's Cassini spacecraft finds a causal link between mysterious, periodic signals from Saturn's magnetic field and explosions of hot ionized gas, known as plasma, around the planet.

Scientists have found that enormous clouds of plasma periodically bloom around Saturn and move around the planet like an unbalanced load of laundry on spin cycle. The movement of this hot plasma produces a repeating signature "thump" in measurements of Saturn's rotating magnetic environment and helps to illustrate why scientists have had such a difficult time measuring the length of a day on Saturn.

"This is a breakthrough that may point us to the origin of the mysteriously changing periodicities that cloud the true rotation period of Saturn," said Pontus Brandt, the lead author on the paper and a Cassini team scientist based at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "The big question now is why these explosions occur periodically."
The data show how plasma injections, electrical currents and Saturn's magnetic field -- phenomena that are invisible to the human eye -- are partners in an intricate choreography. Periodic plasma explosions form islands of pressure that rotate around Saturn. The islands of pressure "inflate" the magnetic field.

The visualization shows how invisible hot plasma in Saturn's magnetosphere – the magnetic bubble around the planet -- explodes and distorts magnetic field lines in response to the pressure. Saturn's magnetosphere is not a perfect bubble because it is blown back by the force of the solar wind, which contains charged particles streaming off the sun.

The force of the solar wind stretches the magnetic field of the side of Saturn facing away from the sun into a so-called magnetotail. The collapse of the magnetotail appears to kick off a process that causes the hot plasma bursts, which in turn inflate the magnetic field in the inner magnetosphere.

Scientists are still investigating what causes Saturn's magnetotail to collapse, but there are strong indications that cold, dense plasma originally from Saturn's moon Enceladus rotates with Saturn. Centrifugal forces stretch the magnetic field until part of the tail snaps back.

The snapping back heats plasma around Saturn and the heated plasma becomes trapped in the magnetic field. It rotates around the planet in islands at the speed of about 100 kilometers per second (200,000 mph). In the same way that high and low pressure systems on Earth cause winds, the high pressures of space cause electrical currents. Currents cause magnetic field distortions.

A radio signal known as Saturn Kilometric Radiation, which scientists have used to estimate the length of a day on Saturn, is intimately linked to the behavior of Saturn's magnetic field. Because Saturn has no surface or fixed point to clock its rotation rate, scientists inferred the rotation rate from timing the peaks in this type of radio emission, which is assumed to surge with each rotation of a planet. This method has worked for Jupiter, but the Saturn signals have varied. Measurements from the early 1980s taken by NASA's Voyager spacecraft, data obtained in 2000 by the ESA/NASA Ulysses mission, and Cassini data from about 2003 to the present differ by a small, but significant degree. As a result, scientists are not sure how long a Saturn day is.

"What's important about this new work is that scientists are beginning to describe the global, causal relationships between some of the complex, invisible forces that shape the Saturn environment," said Marcia Burton, the Cassini fields and particles investigation scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The new results still don't give us the length of a Saturn day, but they do give us important clues to begin figuring it out. The Saturn day length, or Saturn's rotation rate, is important for determining fundamental properties of Saturn, like the structure of its interior and the speed of its winds."

Plasma is invisible to the human eye. But the ion and neutral camera on Cassini's magnetospheric imaging instrument provides a three-dimensional view by detecting energetic neutral atoms emitted from the plasma clouds around Saturn. Energetic neutral atoms form when cold, neutral gas collides with electrically-charged particles in a cloud of plasma. The resulting particles are neutrally charged, so they are able to escape magnetic fields and zoom off into space. The emission of these particles often occurs in the magnetic fields surrounding planets.

By stringing together images obtained every half hour, scientists produced movies of plasma as it drifted around the planet. Scientists used these images to reconstruct the 3-D pressure produced by the plasma clouds, and supplemented those results with plasma pressures derived from the Cassini plasma spectrometer. Once scientists understood the pressure and its evolution, they could calculate the associated magnetic field perturbations along the Cassini flight path. The calculated field perturbation matched the observed magnetic field "thumps" perfectly, confirming the source of the field oscillations.

"We all know that changing rotation periods have been observed at pulsars, millions of light years from our solar system, and now we find that a similar phenomenon is observed right here at Saturn," said Tom Krimigis, principal investigator of the magnetospheric imaging instrument, also based at the Applied Physics Laboratory and the Academy of Athens, Greece. "With instruments right at the spot where it's happening, we can tell that plasma flows and complex current systems can mask the real rotation period of the central body. That's how observations in our solar system help us understand what is seen in distant astrophysical objects."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif. manages the mission for NASA's Science Mission Directorate, Washington, D.C. The magnetic imaging instrument team is based at the Johns Hopkins University Applied Physics Laboratory, Laurel, Md.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-417

Monday, December 13, 2010

Satellites Pinpoint Drivers of Urban Heat Islands in the Northeast

0 comments
Cities such as New York, Philadelphia, and Boston are prominent centers of political power. Less known: Their size, background ecology, and development patterns also combine to make them unusually warm, according to NASA scientists who presented new research recently at an American Geophysical Union (AGU) meeting in San Francisco, Calif.

Summer land surface temperature of cities in the Northeast were an average of 7 °C to 9 °C (13°F to 16 °F) warmer than surrounding rural areas over a three year period, the new research shows. The complex phenomenon that drives up temperatures is called the urban heat island effect.

Heat islands are not a newly-discovered phenomenon. Indeed, using simple mercury thermometers, weather watchers have noticed for some two centuries that cities tend to be warmer than surrounding rural areas.

Likewise, researchers have long noticed that the magnitude of heat islands can vary significantly between cities. However, accurate comparisons have long eluded scientists because ground-based air temperature sensors tend to be unevenly distributed and prone to local bias. The lack of quantifiable definitions for urban versus non-urban areas has also hindered comparisons.

Satellite technology, which offers a more uniform view of heat islands, is in the process of changing this. The group of researchers from NASA’s Goddard Space Flight Center in Greenbelt, Md., presented results based on a new method for comparing heat islands at the AGU meeting.

"This, at least to our knowledge, is the first time that anybody has systematically compared the heat islands of a large number of cities at continental and global scales," said Ping Zhang, a scientist at Goddard and the lead author of the research.Development produces heat islands by replacing vegetation, particularly forests, with pavement and other urban infrastructure. This limits plant transpiration, an evaporative process that helps cool plant leaves and also cools air temperatures, explained Robert Wolfe of Goddard, one of the scientists who developed the method.

Dark city infrastructure, such as black roofs, also makes urban areas more apt to absorb and retain heat. Heat generated by motor vehicles, factories, and homes also contributes to the development of urban heat islands.

A New View

The new method for comparing cities, which the team of scientists has honed for about two years, involves the use of maps of impervious surface area produced by a United States Geological Survey-operated Landsat satellite, and land surface temperature data from the Moderate-resolution Imaging Spectroradiometer (MODIS), an instrument aboard NASA's Aqua and Terra satellites.

Impervious surfaces are surfaces that don't absorb water easily, such as roads, roofs, parking lots, and sidewalks. Land surface temperatures tend to be higher and more variable than air temperatures, but the two generally vary in sync with each other.

By analyzing data from thousands of settlements around the world, the Goddard team has pinpointed key characteristics of cities that drive the development of heat islands. The largest cities, their analysis shows, usually have the strongest heat islands. Cities located in forested regions, such as the northeastern United States, also have stronger heat islands than cities situated in grassy or desert environments.

Most recently, the Goddard group has shown that a city's development patterns -- whether a city is sprawling or compact -- can also affect the strength of its heat island.

By comparing 42 cities in the Northeast, they found that densely-developed cities with compact urban cores are more apt to produce strong urban heat islands than more sprawling, less intensely-developed cities.

The compact city of Providence, R.I., for example, has surface temperatures that are about 12.2 °C (21.9 °F) warmer than the surrounding countryside, while similarly-sized but spread-out Buffalo, N.Y., produces a heat island of only about 7.2 °C (12.9 °F), according to satellite data. Since the background ecosystems and sizes of both cities are about the same, Zhang's analysis suggests development patterns are the critical difference.

She found that land cover maps show that about 83 percent of Providence is very or moderately densely-developed. Buffalo, in contrast, has dense development patterns across just 46 percent of the city. Providence also has dense forested areas ringing the city, while Buffalo has a higher percentage of farmland. "This exacerbates the effect around Providence because forests tend to cool areas more than crops do," explained Wolfe.

Cities in desert regions, such as Las Vegas, in contrast, often have weak heat islands or are actually cooler than the surrounding rural area. Providence, R.I.; Washington, D.C.; Philadelphia, Pa.; Baltimore, Md.; Boston, Ma.; and Pittsburgh, Pa.; had some of the strongest heat islands of the 42 northeastern cities analyzed.

"The urban heat island is a relative measure comparing the temperature of the urban core to the surrounding area," said Marc Imhoff, the leader of the Goddard research group. "As a result, the condition of the rural land around the city matters a great deal."

Heat Island Impacts

Ratcheting up temperatures can have significant -- and deadly -- consequences for cities. Heat islands not only cause air conditioner and electricity usage to surge, but they also increase the mortality of elderly people and those with pre-existing respiratory and cardiovascular illness.

The U.S. Environmental Protection Agency estimates that, between 1979 and 2003, heat exposure has caused more than the number of mortalities resulting from hurricanes, lightning, tornadoes, floods, and earthquakes combined.

"It is the lack of cooling at nighttime, rather than high daytime temperatures, that poses a health risk," said Benedicte Dousset, a scientist from the University of Hawaii who also presented data about heat islands at the AGU meeting.

Dousset recently analyzed surface temperature images of Paris and showed the spatial distribution of heat-related deaths during a sweltering heat wave in 2003. Some 4,800 premature deaths occurred in Paris during the event, and excess mortality across Europe is thought to be about 70,000.

The risk of death was highest at night in areas where land surface temperatures were highest, she found. Buildings and other infrastructure absorb sensible heat during the day and reradiate it throughout the night, but the cooling effect of evaporation is absent in cities. The lack of relief, particularly among the elderly population, can be deadly, she explained.

Ramped up air conditioning usage may have even exacerbated the problem, other data presented at the meeting suggests. Cecile de Munck, of the French Centre for Meteorological Research of Meteo-France, conducted a series of modeling experiments that show excess heat expelled onto the streets because of increased air conditioner usage during heat waves can elevate outside street temperatures significantly.

"The finding raises the question: what can we do to design our cities in ways that will blunt the worst effects of heat islands?" said de Munck, who notes also that her research shows that some types of air conditioning exacerbate heat islands more than others.

Making sure cities have trees and parks interspersed throughout the compact urban cores can also help defend against heat islands. And studies shows that painting the surfaces of roads and buildings white instead of black and creating “green” roofs that include vegetation can soften urban heat islands.

"There's no one solution, and it's going to be different for every city," said Dousset. "Heat islands are complex phenomena."

For more information visit http://www.nasa.gov/topics/earth/features/heat-island-sprawl.html

Sunday, December 12, 2010

Mars Odyssey All Stars - Bunge Crater Dunes

0 comments
Fans and ribbons of dark sand dunes creep across the floor of Bunge Crater in response to winds blowing from the direction at the top of the picture. The frame is about 14 kilometers (9 miles) wide.

This image was taken in January 2006 by the Thermal Emission Imaging System instrument on NASA's Mars Odyssey orbiter and posted in a special December 2010 set marking the occasion of Odyssey becoming the longest-working Mars spacecraft in history. The pictured location on Mars is 33.8 degrees south latitude, 311.4 degrees east longitude.

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Science Mission Directorate, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

For more information visit http://www.nasa.gov/mission_pages/odyssey/images/pia13654b.html

Friday, December 10, 2010

The Greatest Stars

0 comments
The small open star cluster Pismis 24 lies in the core of the NGC 6357 nebula in Scorpius, about 8,000 light-years away from Earth. The brightest object in the center of this image is designated Pismis 24-1 and was once thought to weigh as much as 200 to 300 solar masses. This would not only have made it by far the most massive known star in the galaxy, but would have put it considerably above the currently believed upper mass limit of about 150 solar masses for individual stars.

However, Hubble Space Telescope high-resolution images of the star show that it is really two stars orbiting one another that are each estimated to be 100 solar masses.

In addition, spectroscopic observations with ground-based telescopes further reveal that one of the stars is actually a tight binary that is too compact to be resolved even by Hubble. This divides the estimated mass for Pismis 24-1 among the three stars. Although the stars are still among the heaviest known, the mass limit has not been broken due to the multiplicity of the system.

The images of NGC 6357 were taken with Hubble's Wide Field and Planetary Camera 2 in April 2002.

For more information visit http://www.nasa.gov/multimedia/imagegallery/image-feature_1818.html

Thursday, December 9, 2010

Odyssey Orbiter Nears Martian Longevity Record

0 comments
By the middle of next week, NASA's Mars Odyssey orbiter will have worked longer at Mars than any other spacecraft in history.

Odyssey entered orbit around Mars on Oct. 24, 2001. On Dec. 15, the 3,340th day since that arrival, it will pass the Martian career longevity record set by its predecessor, Mars Global Surveyor, which operated in orbit from Sept. 11, 1997, to Nov. 2, 2006.

Odyssey made its most famous discovery -- evidence for copious water ice just below the dry surface of Mars -- during its first few months, and it finished its radiation-safety check for future astronauts before the end of its prime mission in 2004. The bonus years of extended missions since then have enabled many accomplishments that would not have been possible otherwise.

"The extra years have allowed us to build up the highest-resolution maps covering virtually the entire planet," said Odyssey Project Scientist Jeffrey Plaut of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

The maps are assemblages of images from the orbiter's Thermal Emission Imaging System (THEMIS) camera, provided and operated by Arizona State University, Tempe.

The orbiter's longevity has given Odyssey scientists the opportunity to monitor seasonal changes on Mars year-to-year, such as the cycle of carbon-dioxide freezing out of the atmosphere in polar regions during each hemisphere's winter. "It is remarkable how consistent the patterns have been from year to year, and that's a comparison that wouldn't have been possible without our mission extensions," Plaut said.

Odyssey's performance has boosted benefits from other missions, too. When NASA's Mars Exploration Rovers, Spirit and Opportunity, far exceeded their own expected lifetimes, Odyssey remained available as the rover's primary communication relay. Nearly all the science data from the rovers and NASA's Phoenix Mars Lander has reached Earth via Odyssey relay. Odyssey also became the middle segment of continuous observation of Martian weather by a series of NASA orbiters: Mars Global Surveyor, Odyssey, and NASA's Mars Reconnaissance Orbiter, which began its science mission in late 2006.

A continuing partnership between JPL and Lockheed Martin Space Systems, Denver, operates Odyssey.

"Hundreds of people who built the Odyssey spacecraft here, in addition to the much smaller crew operating it today, have great pride in seeing the spacecraft achieve this milestone," said Bob Berry, Odyssey program manager at Lockheed Martin Space Systems Company.

Odyssey's science triumphs began in early 2002 with detection of hydrogen just below the surface throughout the planet's high-latitude regions. Deduction that the hydrogen is in frozen water prompted the Phoenix mission, which confirmed that fact in 2008.

Investigators at the University of Arizona, Tucson, have headed the operation of Odyssey's Gamma Ray Spectrometer suite of instruments, which detected the hydrogen and subsequently mapped the distribution of several other elements on Mars. Additional science partners are located at the Russian Aviation and Space Agency, which provided the suite's high-energy neutron detector, and at Los Alamos National Laboratories, New Mexico, which provided the neutron spectrometer.

The mission's science goal of checking radiation levels around Mars to aid planning of future human missions was completed by the Mars Radiation Environment Experiment, developed at NASA Johnson Space Center, Houston.

NASA has planned future work for Odyssey, in addition to having the orbiter continue its own science and its relay service for the Mars Exploration Rover mission. If required, controllers will adjust Odyssey's orbit so the spacecraft is in a favorable position for a communication relay role during the August 2012 landing of NASA's next Mars rover, Curiosity.

Mars Odyssey, launched April 7, 2001, is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington.

For more information visit http://www.nasa.gov/mission_pages/odyssey/odyssey20101209.html

Tuesday, December 7, 2010

Inception

0 comments
Backdropped by a sunset, the Canadarm2 was operated by the crew of the International Space Station. The crew of space shuttle Discovery on the STS-105 mission took this image from a window on the flight deck.

In this image from August 2001, the station had seen less than one year of human habitation.


For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1816.html

Monday, December 6, 2010

Double Vision: New Instrument Casts Its Eyes to the Sky

0 comments
The Large Binocular Telescope Interferometer has taken its first images of the star Beta Peg in the constellation Pictor -- an encouraging start for an instrument designed to probe the cosmic neighborhoods where Earth-like planets could exist.

Eight years in development, the NASA-funded instrument combines beams of light from twin 8.4-meter (28-foot) mirrors mounted atop the Large Binocular Telescope on Mount Graham, Ariz. "By combining the light of the telescopes, we're able to realize its full potential," said Project Manager Tom McMahon of the University of Arizona, Tucson. "Together, the two mirrors form the largest single-mount telescope in the world."

"The quality of the first-light images is wonderful," said the principal investigator for the project, Phil Hinz of the University of Arizona. "The telescope was stable and the instrument was working properly."

With this high-resolution imaging capability, astronomers hope to probe nearby solar systems -- specifically, the areas in these systems where Earth-like planets with liquid water could exist. Though the Large Binocular Telescope Interferometer won't be able to detect Earth-size planets, it will be able to see dust disks that are indicative of planet formation, in addition to detecting large, Jupiter-size planets farther out from the star. These findings will help future, space-based exoplanet missions know where to search for Earth-like planets in our own galactic neighborhood.

With its ability to probe this "habitable zone" of other solar systems, the Large Binocular Telescope Interferometer will also complement the capabilities of other NASA missions -- the Keck Interferometer, which can find dust very close to stars; and the Spitzer Space Telescope, which is adept at observing planet-forming dust that is much more distant.

"This instrument will help complete our picture of what planetary systems look like and be a pathfinder for finding Earth-like planets that are close by," Hinz said.

With a major upgrade of the Large Binocular Telescope's adaptive optics system scheduled for next year, the interferometer will undergo testing and commissioning for the majority of 2011, and during that time, scientific observations will begin.

"This is the highest-resolution instrument of its kind in the world," McMahon said. "We won't just be able to image exoplanets, but extragalactic objects, nebulae and galaxies. It's taken time to make sure it works as envisioned, but now it's time to do science."

The Large Binocular Telescope Interferometer is funded by NASA and managed by Ben Parvin at NASA's Jet Propulsion Laboratory, Pasadena, Calif., as part of NASA's Exoplanet Exploration Program. The instrument and product development are provided by the University of Arizona, Tucson.


For more information visit http://www.nasa.gov/topics/universe/features/lbti20101206.html

Sunday, December 5, 2010

NASA and Republic of Korea Representatives Hold Bilateral Meeting

0 comments
A delegation from the Republic of Korea’s Ministry of Education, Science and Technology (MEST), headed by Director General Dae-Soo Yoon, and the Korea Aerospace Research Institute, led by Director Chin-Young Hwang, visited NASA Headquarters in Washington, D.C., on De. 1, 2010, for the 2010 MEST-NASA bilateral meeting. During the meeting, which was hosted by Michael O’Brien, NASA Associate Administrator for International and Interagency Relations, NASA and MEST reviewed the progress of cooperative activities over the past year and discussed plans for future cooperation.

“It was an honor to host our Republic of Korea colleagues for this bilateral meeting,” said O'Brien. “Our agencies are enthusiastic about the two agreements we recently signed and look forward to the concrete collaboration that will result. Our discussions identified potential areas of additional cooperation which look very promising.”

Over the past two years, MEST and NASA have taken steps to strengthen aerospace cooperation between the United States and Korea, including: signing a Joint Statement of Intent for Cooperation in Civil Space and Aeronautics Activities; convening the MEST-NASA Bilateral Meeting; drafting a NASA-MEST Joint Report Regarding Potential Opportunities for Enhanced Cooperation; and signing international agreements in the areas of space geodesy, solar and space physics and space weather research.


For more information visit http://www.nasa.gov/topics/people/features/NASA_Korea_agreement.html

Thursday, December 2, 2010

'S' is for Space Station

0 comments
Astronauts aboard the International Space Station are helping children learn their ABC's and vocabulary through educational demonstrations of how they live and work in space.

NASA collaborated with Sesame Workshop, including the popular children’s television programs, "Sesame Street" and "The Electric Company," to create science, technology, engineering and math-related education resources, or STEM, for children ages 2-5.

"The space station environment provides a unique classroom in space to teach young children about the words such as 'float' and 'astronaut' by showing them how astronauts float in space," said Matthew Keil in the Teaching from Space Office at NASA's Johnson Space Center in Houston.

Space station astronaut Soichi Noguchi completed four educational videos for "Sesame Street" during his stay on the International Space Station from December 2009 to June 2010. The four videos are airing on "Sesame Street" throughout the fall 2010 season. On the episode "F is for Float" -- show number 4214 -- Noguchi held up the letter "F" to represent the word "float" while he floated around the space station to demonstrate the word.

"Word on the Street" -- show number 4222 -- featured Noguchi explaining to the character "Murray" what the word "float" means, using similar demonstrations with a lemon, socks and a ball.

On the episode "A is for Astronaut" -- show number 4225 -- Noguchi held up the letter "A" to represent the word "astronaut." Noguchi sounded out the letter and the word for children.

On the "Countdown to Space" episode -- show number 4234 airing on PBS December 27 -- Noguchi counted down from 10 to one. Noguchi counted down and said "blast-off!" while floating from the floor to the ceiling.

Sesame Workshop approached the NASA Teaching from Space Office for assistance in implementing more science and math curriculum into their programming by using the unique educational environment of the space station, NASA centers and facilities and the unique people who work at NASA.

"I am an educator who is very interested in making connections between curriculum and everyday life experiences that students encounter," said Keil. "There are many teachable moments that exist in every NASA mission. Our job is to make sure educators and students are aware of these moments and assist them in connecting these moments to what they are teaching or learning in school and at home."

For more information visit http://www.nasa.gov/mission_pages/station/research/news/sesame.html

Wednesday, December 1, 2010

Solar Observation Mission Celebrates 15 Years

0 comments
On December 2, 1995, the Solar and Heliospheric Observatory or SOHO was launched into space from Cape Canaveral aboard an Atlas IIAS rocket. The joint ESA/NASA project began its work observing the sun at a time when the term "solar weather" was almost never used.

Fifteen years later, SOHO has revolutionized what we know about the solar atmosphere and violent solar storms produced by the sun. SOHO has become an expert comet-hunter, nightly news leader and a workhorse that helped create the field of near-real-time space weather reporting as we know it –- but it started as a tool to answer three scientific questions about the sun.

"We were looking for answers to three long-standing problems in solar physics," said Joe Gurman, “the solar neutrino problem, the coronal heating mystery, and the question of what causes solar wind acceleration." Gurman works at NASA's Goddard Space Flight Center in Greenbelt, Md., and has been the U.S. project scientist for SOHO since 1998.

Placed into orbit around the L1 Lagrangian point between Earth and the sun, SOHO was able to observe the sun continuously without Earth ever obstructing its view. With its uninterrupted observations, says Gurman, SOHO has significantly helped with all three original questions.

First, the so-called solar neutrino problem was a conflict between how many neutrinos were predicted by fusion and models of the solar interior versus how many were in fact detected. SOHO confirmed that the interior models were correct and helped show that, instead, the detectors were not finding all the neutrinos since they were changing after they left the sun. Second is the coronal heating mystery, so called because the Sun's outermost atmosphere, or corona, is unexpectedly hundreds of times hotter than the sun's surface. SOHO helped determine that the movement of the Sun’s small-scale magnetic fields themselves could contribute, in principle, sufficient energy to heat the corona. Third, SOHO observed that the acceleration of the solar wind appears to be powered by a special kind of waves that can accelerate certain particles preferentially.

SOHO is perhaps best known for its observations of coronal mass ejections, or CMEs. These blasts of gas and magnetic fields are a fundamental concern for those who track and attempt to forecast space weather. But when SOHO launched in 1995, there was disagreement over what a CME headed for earth looked like. The first ever videos of a CME wave in the lower corona in April of 1997, combined with SOHO’s white light coronagraph observations of the accompanying “halo” CME, changed all that.

Steele Hill, who leads public outreach for SOHO at Goddard, had then only been working for the SOHO team for six months. "It was the first time we had witnessed an event like that. We could track it, predict its direction, and say that in two to three days it will have some impact on Earth.” Hill pulled together some SOHO files and made a movie. . . and it was the first story on the national news that night in April 1997.

An unexpected destiny for SOHO is that it has become the greatest comet-finder of all time. With its data stream available publicly, anyone can be a comet hunter -- and as of November 1, 2010, SOHO had spotted more than 1,940 of them.

After a good 15-years, SOHO isn't easing in to retirement yet. A long archive of data such as SOHO's is necessary to spot some of the tiniest waves that propagate through the body of the sun. Known as buoyancy or gravity-mode waves, these waves only disturb the surface of the sun at a speed of a millimeter per second.

"That's a pretty hard measurement to do," says Gurman. "With 15 years of observations, we just might have a strong enough signal."

In addition, SOHO is still our only solar observatory to have gathered images of the sun during a solar maximum. The last maximum was in 2000. As we move into the next peak in 2013, it will be SOHO's legacy that allows scientists to compare and contrast what we see now in newer missions such as the Solar Dynamics Observatory (SDO) and the Solar TErrestrial RElations Observatory (STEREO) to what was seen then.

"Every mission stands on the shoulders of the missions that came before it," says Gurman. "Without the success of SOHO we never would have had the opportunity to get even better measurements with STEREO, Hinode, and SDO."


For more information visit http://www.nasa.gov/mission_pages/soho/15-years.html