Friday, July 25, 2014

Shining a Light on Cool Pools of Gas in the Galaxy

Shining a Light on Cool Pools of Gas in the Galaxy:

This illustration shows a newfound reservoir of stellar fuel discovered by the Herschel space observatory (red)
This illustration shows a newfound reservoir of stellar fuel discovered by the Herschel space observatory (red). Image credit: ESA/NASA/JPL-Caltech

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June 11, 2013

Newly formed stars shine brightly, practically crying out, "Hey, look at me!" But not everything in our Milky Way galaxy is easy to see. The bulk of material between the stars in the galaxy -- the cool hydrogen gas from which stars spring -- is nearly impossible to find.


A new study from the Hershel Space Observatory, a European Space Agency mission with important NASA participation, is shining a light on these hidden pools of gas, revealing their whereabouts and quantities. In the same way that dyes are used to visualize swirling motions of transparent fluids, the Herschel team has used a new tracer to map the invisible hydrogen gas.


The discovery reveals that the reservoir of raw material for making stars had been underestimated before -- almost by one third -- and extends farther out from our galaxy's center than known before.


"There is an enormous additional reservoir of material available to form new stars that we couldn't identify before," said Jorge Pineda of NASA's Jet Propulsion Laboratory, Pasadena, Calif., lead author of a new paper on the findings published in the journal Astronomy and Astrophysics.


"We had to go to space to solve this mystery because our atmosphere absorbs the specific radiation we wanted to detect," said William Langer of JPL, principal investigator of the Herschel project to map the gas. "We also needed to see far-infrared light to pinpoint the location of the gas. For both these reasons, Herschel was the only telescope for the job."


Stars are created from clouds of gas, made of hydrogen molecules. The first step in making a star is to squeeze gas together enough that atoms fuse into molecules. The gas starts out sparse but, through the pull of gravity and sometimes other constricting forces, it collects and becomes denser. When the hydrogen gets dense enough, nuclear fusion takes place and a star is born, shining with starlight.


Astronomers studying stars want to follow this journey, from a star's humble beginnings as a cloud of molecules to a full-blown blazing orb. To do so requires mapping the distribution of the stellar hydrogen fuel across the galaxy. Unfortunately, most hydrogen molecules in space are too cold to give off any visible light. They lurk unseen by most telescopes.


For decades, researchers have turned to a tracer molecule called carbon monoxide, which goes hand-in-hand with the hydrogen molecules, revealing their location. But this method has limitations. In regions where the gas is just beginning to pool -- the earliest stage of cloud formation -- there is no carbon monoxide.


"Ultraviolet light destroys the carbon monoxide," said Langer. "In the space between stars, where the gas is very thin, there is not enough dust to shield molecules from destruction by ultraviolet light."


A different tracer -- ionized carbon - does, however, linger in these large but relatively empty spaces, and can be used to pin down the hydrogen molecules. Researchers have observed ionized carbon from space before, but Herschel has, for the first time, provided a dramatically improved geographic map of its location and abundance in the galaxy.


"Thanks to Herschel's incredible sensitivity, we can separate material moving at different speeds," said Paul Goldsmith, a co-author and the NASA Herschel Project Scientist at JPL. "We finally can get the whole picture of what's available to make future generations of stars."


Read a more in-depth story about this research from the European Space Agency at http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=51909 . The technical paper is online at http://arxiv.org/abs/1304.7770 .


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


More information is online at http://www.herschel.caltech.edu , http://www.nasa.gov/herschel and http://www.esa.int/SPECIALS/Herschel .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-199
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Mars Water-Ice Clouds Are Key to Odd Thermal Rhythm

Mars Water-Ice Clouds Are Key to Odd Thermal Rhythm:

This graphic depicts the Mars Climate Sounder instrument on NASA's Mars Reconnaissance Orbiter measuring the temperature of a cross section of the Martian atmosphere as the orbiter passes above the south polar region
This graphic depicts the Mars Climate Sounder instrument on NASA's Mars Reconnaissance Orbiter measuring the temperature of a cross section of the Martian atmosphere as the orbiter passes above the south polar region.

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June 12, 2013

PASADENA, Calif. -- Researchers using NASA's Mars Reconnaissance Orbiter have found that temperatures in the Martian atmosphere regularly rise and fall not just once each day, but twice.


"We see a temperature maximum in the middle of the day, but we also see a temperature maximum a little after midnight," said Armin Kleinboehl of NASA's Jet Propulsion Laboratory in Pasadena, Calif., who is the lead author of a new report on these findings.


Temperatures swing by as much as 58 degrees Fahrenheit (32 kelvins) in this odd, twice-a-day pattern, as detected by the orbiter's Mars Climate Sounder instrument.


The new set of Mars Climate Sounder observations sampled a range of times of day and night all over Mars. The observations found that the pattern is dominant globally and year-round. The report is being published in the journal Geophysical Research Letters.


Global oscillations of wind, temperature and pressure repeating each day or fraction of a day are called atmospheric tides. In contrast to ocean tides, they are driven by variation in heating between day and night. Earth has atmospheric tides, too, but the ones on Earth produce little temperature difference in the lower atmosphere away from the ground. On Mars, which has only about one percent as much atmosphere as Earth, they dominate short-term temperature variations throughout the atmosphere.


Tides that go up and down once per day are called "diurnal." The twice-a-day ones are called "semi-diurnal." The semi-diurnal pattern on Mars was first seen in the 1970s, but until now it had been thought to appear just in dusty seasons, related to sunlight warming dust in the atmosphere.


"We were surprised to find this strong twice-a-day structure in the temperatures of the non-dusty Mars atmosphere," Kleinboehl said. "While the diurnal tide as a dominant temperature response to the day-night cycle of solar heating on Mars has been known for decades, the discovery of a persistent semi-diurnal response even outside of major dust storms was quite unexpected, and caused us to wonder what drove this response."


He and his four co-authors found the answer in the water-ice clouds of Mars. The Martian atmosphere has water-ice clouds for most of the year. Clouds in the equatorial region between about 6 to 19 miles (10 to 30 kilometers) above the surface of Mars absorb infrared light emitted from the surface during daytime. These are relatively transparent clouds, like thin cirrus clouds on Earth. Still, the absorption by these clouds is enough to heat the middle atmosphere each day. The observed semi-diurnal temperature pattern, with its maximum temperature swings occurring away from the tropics, was also unexpected, but has been replicated in Mars climate models when the radiative effects of water-ice clouds are included.


"We think of Mars as a cold and dry world with little water, but there is actually more water vapor in the Martian atmosphere than in the upper layers of Earth's atmosphere," Kleinboehl said. "Water-ice clouds have been known to form in regions of cold temperatures, but the feedback of these clouds on the Mars temperature structure had not been appreciated. We know now that we will have to consider the cloud structure if we want to understand the Martian atmosphere. This is comparable to scientific studies concerning Earth's atmosphere, where we have to better understand clouds to estimate their influence on climate."


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


For more about the Mars Reconnaissance Orbiter, visit: http://www.nasa.gov/mro .

Guy Webster 818-354-6278

Jet Propulsion Laboratory, Pasadena, Calif.

guy.webster@jpl.nasa.gov


Dwayne Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov


2013-201
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The Turbulent, High-Energy Sky Is Keeping NuSTAR Busy

The Turbulent, High-Energy Sky Is Keeping NuSTAR Busy:

Artist's concept of NuSTAR in orbit.
Artist's concept of NuSTAR in orbit. NuSTAR has a 33-foot (10-meter) mast that deploys after launch to separate the optics modules (right) from the detectors in the focal plane (left). Image credit: NASA/JPL-Caltech

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June 17, 2013

NuSTAR Status Update


NuSTAR has been busy studying the most energetic phenomena in the universe. Recently, a few high-energy events have sprung up, akin to "things that go bump in the night." When one telescope catches a sudden outpouring of high-energy light in the sky, NuSTAR and a host of other telescopes stop what they were doing and take a better look.


For example, in early April, the blazar Markarian 421 had an episode of extreme activity, brightening by more than 50 times its typical level. Blazars are a special class of galaxies with accreting, or "feeding," supermassive black holes at their centers. As the black holes feed, they light up, often ejecting jets of material. When the jets are pointing toward Earth, they are called blazars. By using telescopes sensitive to a range of energies to study how blazars vary, astrophysicists gain insight into black hole feeding processes and the physical conditions near the black hole.


NuSTAR got lucky in the case of Markarian 421, because it was already observing the blazar at the time of its eruption, simultaneously with other telescopes, including NASA's Fermi and Swift satellites. The flare-up was the brightest ever observed for this object. In fact, it was so bright that NuSTAR and other telescopes changed their observing cadence to spend more time studying this galaxy. More on these findings will be available after the scientists have analyzed the data and published papers.


Just a few weeks after this event, towards the end of April, NASA's Swift satellite noticed the region around the center of our own Milky Way galaxy had suddenly lit up. Flares lasting from a few minutes to three hours are not uncommon for the black hole in the center of the Milky Way, known as Sagittarius A*. In fact, NuSTAR observed such a flare last July (http://www.nasa.gov/mission_pages/nustar/news/nustar20121023.html). However, this new event had lasted tens of hours and got the whole high-energy community excited. NuSTAR was one of the first "on the scene," observing the galactic center less than 50 hours after the initial Swift discovery. The NuSTAR findings revealed that the brightening was due to a type of neutron star called a magnetar, and not Sagittarius A* itself. The results were written up and accepted in the Astrophysical Journal Letters.


Yet another event popped up in the sky just a few days later, surprising astronomers. Swift found an extremely bright gamma-ray burst, brighter than any event it had previously identified during its nearly 10 years in orbit. A gamma-ray burst is a huge release of energy from a distant galaxy, thought to be triggered by the collapse of a massive star.


The astronomical community, including NuSTAR, quickly reacted to the blast. NuSTAR provided the first focused, high-quality observations of a gamma-ray burst in high-energy X-rays.


Beginning in April, the NuSTAR spacecraft gained use of the Kongsberg Satellite Services' Singapore tracking station for extra command uplinks and data downlinks. The spacecraft's primary tracking coverage is provided by the Italian Space Agency and uses antennas located in Malindi, Kenya, while data uplinks are provided by NASA's Tracking and Data Relay Satellite System (TDRSS) antennas. The back-up Singapore tracking station is helpful for periods when additional coverage is needed either due to high data-rate targets, such as bright objects, or when the Malindi antennas are unavailable. Additional coverage has also been provided by the Universal Space Network's Hawaii antenna.


NuSTAR is a Small Explorer mission led by the California Institute of Technology in Pasadena and managed by NASA's Jet Propulsion Laboratory, also in Pasadena, for NASA's Science Mission Directorate in Washington. The spacecraft was built by Orbital Sciences Corporation, Dulles, Va. Its instrument was built by a consortium including Caltech; JPL; the University of California, Berkeley; Columbia University, New York; NASA's Goddard Space Flight Center, Greenbelt, Md.; the Danish Technical University in Denmark; Lawrence Livermore National Laboratory, Livermore, Calif.; ATK Aerospace Systems, Goleta, Calif.; and with support from the Italian Space Agency Science Data Center.


NuSTAR's mission operations center is at UC Berkeley. The outreach program is based at Sonoma State University, Rohnert Park, Calif. NASA's Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.


For more information, visit http://www.nasa.gov/nustar and http://www.nustar.caltech.edu/ .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.b.clavin@jpl.nasa.gov


2013-203
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Cassini Probe to Take Photo of Earth From Deep Space

Cassini Probe to Take Photo of Earth From Deep Space:

This simulated view from NASA's Cassini spacecraft shows the expected positions of Saturn and Earth on July 19, 2013, around the time Cassini will take Earth's picture.
This simulated view from NASA's Cassini spacecraft shows the expected positions of Saturn and Earth on July 19, 2013, around the time Cassini will take Earth's picture. Cassini will be about 898 million miles (1.44 billion kilometers) away from Earth at the time. That distance is nearly 10 times the distance from the sun to Earth. Image credit: NASA/JPL-Caltech

June 18, 2013

PASADENA, Calif. - NASA's Cassini spacecraft, now exploring Saturn, will take a picture of our home planet from a distance of hundreds of millions of miles on July 19. NASA is inviting the public to help acknowledge the historic interplanetary portrait as it is being taken.


Earth will appear as a small, pale blue dot between the rings of Saturn in the image, which will be part of a mosaic, or multi-image portrait, of the Saturn system Cassini is composing.


"While Earth will be only about a pixel in size from Cassini's vantage point 898 million [1.44 billion kilometers] away, the team is looking forward to giving the world a chance to see what their home looks like from Saturn," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We hope you'll join us in waving at Saturn from Earth, so we can commemorate this special opportunity."


Cassini will start obtaining the Earth part of the mosaic at 2:27 p.m. PDT (5:27 p.m. EDT or 21:27 UTC) and end about 15 minutes later, all while Saturn is eclipsing the sun from Cassini's point of view. The spacecraft's unique vantage point in Saturn's shadow will provide a special scientific opportunity to look at the planet's rings. At the time of the photo, North America and part of the Atlantic Ocean will be in sunlight.


Unlike two previous Cassini eclipse mosaics of the Saturn system in 2006, which captured Earth, and another in 2012, the July 19 image will be the first to capture the Saturn system with Earth in natural color, as human eyes would see it. It also will be the first to capture Earth and its moon with Cassini's highest-resolution camera. The probe's position will allow it to turn its cameras in the direction of the sun, where Earth will be, without damaging the spacecraft's sensitive detectors.


"Ever since we caught sight of the Earth among the rings of Saturn in September 2006 in a mosaic that has become one of Cassini's most beloved images, I have wanted to do it all over again, only better," said Carolyn Porco, Cassini imaging team lead at the Space Science Institute in Boulder, Colo. "This time, I wanted to turn the entire event into an opportunity for everyone around the globe to savor the uniqueness of our planet and the preciousness of the life on it."


Porco and her imaging team associates examined Cassini's planned flight path for the remainder of its Saturn mission in search of a time when Earth would not be obstructed by Saturn or its rings. Working with other Cassini team members, they found the July 19 opportunity would permit the spacecraft to spend time in Saturn's shadow to duplicate the views from earlier in the mission to collect both visible and infrared imagery of the planet and its ring system.


"Looking back towards the sun through the rings highlights the tiniest of ring particles, whose width is comparable to the thickness of hair and which are difficult to see from ground-based telescopes," said Matt Hedman, a Cassini science team member based at Cornell University in Ithaca, N.Y., and a member of the rings working group. "We're particularly interested in seeing the structures within Saturn's dusty E ring, which is sculpted by the activity of the geysers on the moon Enceladus, Saturn's magnetic field and even solar radiation pressure."


This latest image will continue a NASA legacy of space-based images of our fragile home, including the 1968 "Earthrise" image taken by the Apollo 8 moon mission from about 240,000 miles (380,000 kilometers) away and the 1990 "Pale Blue Dot" image taken by Voyager 1 from about 4 billion miles (6 billion kilometers) away.


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the Cassini-Huygens mission for NASA's Science Mission Directorate in Washington, and designed, developed and assembled the Cassini orbiter and its two onboard cameras. The imaging team consists of scientists from the United States, the United Kingdom, France and Germany. The imaging operations center is based at the Space Science Institute in Boulder, Colo.


To learn more about the public outreach activities associated with the taking of the image, visit: http://saturn.jpl.nasa.gov/waveatsaturn .


For more information about Cassini, visit http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Dwayne Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov


2013-204
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Ten Thousandth Near-Earth Object Unearthed in Space

Ten Thousandth Near-Earth Object Unearthed in Space:

Asteroid 2013 MZ5 as seen by the University of Hawaii's PanSTARR-1 telescope.
Asteroid 2013 MZ5 as seen by the University of Hawaii's PanSTARR-1 telescope. In this animated gif, the asteroid moves relative to a fixed background of stars. Asteroid 2013 MZ5 is in the right of the first image, towards the top, moving diagonally left/down. Image credit: PS-1/UH

› Larger view | Unannotated version

June 24, 2013

More than 10,000 asteroids and comets that can pass near Earth have now been discovered. The 10,000th near-Earth object, asteroid 2013 MZ5, was first detected on the night of June 18, 2013, by the Pan-STARRS-1 telescope, located on the 10,000-foot (convert) summit of the Haleakala crater on Maui. Managed by the University of Hawaii, the PanSTARRS survey receives NASA funding.


Ninety-eight percent of all near-Earth objects discovered were first detected by NASA-supported surveys.


"Finding 10,000 near-Earth objects is a significant milestone," said Lindley Johnson, program executive for NASA's Near-Earth Object Observations Program at NASA Headquarters, Washington. "But there are at least 10 times that many more to be found before we can be assured we will have found any and all that could impact and do significant harm to the citizens of Earth." During Johnson's decade-long tenure, 76 percent of the NEO discoveries have been made.


Near-Earth objects (NEOs) are asteroids and comets that can approach the Earth's orbital distance to within about 28 million miles (45 million kilometers). They range in size from as small as a few feet to as large as 25 miles (41 kilometers) for the largest near-Earth asteroid, 1036 Ganymed.


Asteroid 2013 MZ5 is approximately 1,000 feet (300 meters) across. Its orbit is well understood and will not approach close enough to Earth to be considered potentially hazardous.


"The first near-Earth object was discovered in 1898," said Don Yeomans, long-time manager of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif. "Over the next hundred years, only about 500 had been found. But then, with the advent of NASA's NEO Observations program in 1998, we've been racking them up ever since. And with new, more capable systems coming on line, we are learning even more about where the NEOs are currently in our solar system, and where they will be in the future."


Of the 10,000 discoveries, roughly 10 percent are larger than six-tenths of a mile (one kilometer) in size - roughly the size that could produce global consequences should one impact the Earth. However, the NASA NEOO program has found that none of these larger NEOs currently pose an impact threat and probably only a few dozen more of these large NEOs remain undiscovered.


The vast majority of NEOs are smaller than one kilometer, with the number of objects of a particular size increasing as their sizes decrease. For example, there are expected to be about 15,000 NEOs that are about one-and-half football fields in size (460 feet, or 140 meters), and more than a million that are about one-third a football field in size (100 feet, or 30 meters). A NEO hitting Earth would need to be about 100 feet (30 meters) or larger to cause significant devastation in populated areas. Almost 30 percent of the 460-foot-sized NEOs have been found, but less than 1 percent of the 100-foot-sized NEOs have been detected.


When it originated, the NASA-instituted Near-Earth Object Observations Program provided support to search programs run by the Massachusetts Institute of Technology's Lincoln Laboratory (LINEAR); the Jet Propulsion Laboratory (NEAT); the University of Arizona (Spacewatch, and later Catalina Sky Survey) and the Lowell Observatory (LONEOS). All these search teams report their observations to the Minor Planet Center, the central node where all observations from observatories worldwide are correlated with objects, and they are given unique designations and their orbits are calculated.


"When I began surveying for asteroids and comets in 1992, a near-Earth object discovery was a rare event," said Tim Spahr, director of the Minor Planet Center. "These days we average three NEO discoveries a day, and each month the Minor Planet Center receives hundreds of thousands of observations on asteroids, including those in the main-belt. The work done by the NASA surveys, and the other international professional and amateur astronomers, to discover and track NEOs is really remarkable."


Within a dozen years, the program achieved its goal of discovering 90 percent of near-Earth objects larger than 3,300 feet (1 kilometer) in size. In December 2005, NASA was directed by Congress to extend the search to find and catalog 90 percent of the NEOs larger than 500 feet (140 meters) in size. When this goal is achieved, the risk of an unwarned future Earth impact will be reduced to a level of only one percent when compared to pre-survey risk levels. This reduces the risk to human populations, because once an NEO threat is known well in advance, the object could be deflected with current space technologies.


Currently, the major NEO discovery teams are the Catalina Sky Survey, the University of Hawaii's Pan-STARRS survey and the LINEAR survey. The current discovery rate of NEOs is about 1,000 per year.


NASA's Near-Earth Object Observations Program manages and funds the search for, study of and monitoring of asteroids and comets whose orbits periodically bring them close to Earth. The Minor Planet Center is funded by NASA and hosted by the Smithsonian Astrophysical Observatory in Cambridge, MA. JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. More information about asteroids and near-Earth objects is available at: http://neo.jpl.nasa.gov/, http://www.jpl.nasa.gov/asteroidwatch and via Twitter at http://www.twitter.com/asteroidwatch .

DC Agle

Jet Propulsion Lab., Pasadena, Calif.

818-393-9011

agle@jpl.nasa.gov


2013-207
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Trailblazer Sea Satellite Marks its Coral Anniversary

Trailblazer Sea Satellite Marks its Coral Anniversary:

Artist's concept of Seasat
Artist's concept of Seasat. Image Credit: NASA/JPL

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June 27, 2013

"The true worth of a man is not to be found in man himself, but in the colours and textures that come alive in others."


- Albert Schweitzer


History tends to look fondly upon trailblazers, even if they don't necessarily stick around. From musicians and actors to politicians and inventors, our lives are immeasurably enriched by the contributions of visionaries who left us.


So when NASA's Jet Propulsion Laboratory, Pasadena, Calif., launched an experimental satellite called Seasat to study Earth and its seas 35 years ago this week, only to see the mission end just 106 days later due to an unexpected malfunction, some at the time may have looked upon it as a failure. But this spunky satellite, which is still in orbit, shining in the night sky at magnitude 4.0, continues to live on through the many Earth and space observation missions it has spawned.


Seasat's tale began in 1969, when a group of engineers and scientists from multiple institutions convened at a conference in Williamstown, Mass., to study how satellites could be used to improve our understanding of the ocean. Three years later, NASA began planning for Seasat, the first multi-sensor spacecraft dedicated specifically to observing Earth's ocean. A broad user working group from many organizations defined its requirements. JPL was selected to manage the project, and numerous other NASA centers and government and industry partners participated. On the night of June 26, 1978, Seasat was launched from California's Vandenberg Air Force Base aboard an Atlas-Agena rocket, carrying with it three prototype radar instruments and two radiometers.


During its brief life, Seasat collected more information about ocean physics than had been acquired in the previous 100 years of shipboard research. It established satellite oceanography and proved the viability of several radar sensors, including an imaging radar, for studying our planet. Most importantly, it spawned many subsequent Earth remote-sensing satellites and instruments at JPL and elsewhere that track changes in Earth's ocean, land and ice, including many currently in orbit or in development. Its advances were also subsequently applied to missions to study other planets.


Post-Seasat NASA program manager Stan Wilson said Seasat demonstrated the potential usefulness of ocean microwave observations. "As a result, at least 50 satellites have been launched by more than a dozen space agencies to carry microwave instruments to observe the ocean. In addition, we have two continuing records of critical climate change in the ocean that are impacting society today: diminishing ice cover in the Arctic and rising global sea level. What greater legacy could a mission have?"


"Seasat flew long enough to fully demonstrate its groundbreaking remote sensing technologies, and its early death permitted the limited available resources to be marshaled toward processing and analyzing its approximately 100-day data set," said Bill Townsend, Seasat radar altimeter experiment manager. "This led to other systems, both nationally and internationally, that continued Seasat's legacy, enabling Seasat technologies to be used to better understand climate change."


Seasat's experimental instruments included a synthetic aperture radar (SAR), which provided the first-ever highly detailed radar images of ocean and land surfaces from space; a radar scatterometer, which measured near-surface wind speed and direction; a radar altimeter, which measured ocean surface height, wind speed and wave heights; and a scanning multichannel microwave radiometer that measured atmospheric and ocean data, including wind speeds, sea ice cover, atmospheric water vapor and precipitation, and sea surface temperatures in both clear and cloudy conditions.


On June 28, the Alaska Satellite Facility will release newly processed digital SAR imagery from Seasat. The imagery, available for download at http://www.asf.alaska.edu , will enable scientists to travel back in time to research the ocean, sea ice, volcanoes, forests, land cover, glaciers and more. Before now, only about 20 percent of Seasat SAR data had been processed digitally.


In oceanography, Seasat gave us our first global view of ocean circulation, waves and winds, providing new insights into the links between the ocean and atmosphere that drive our climate. For the first time, the state of an entire ocean could be seen all at once. Seasat's altimeter, which used pulses of microwave radiation to measure the distance from the satellite to the ocean surface precisely, mapped ocean surface topography, allowing scientists to demonstrate how sea surface conditions could be used to determine ocean circulation and heat storage. The data also revealed new information about Earth's gravity field and the topography of the ocean floor.


"The short 100-day Seasat mission provided a moment of epiphany to remind people that the vast ocean is best accessed from space," said Lee-Lueng Fu, JPL senior research scientist and project scientist for the NASA/French Space Agency Jason-1 satellite and NASA's planned Surface Water and Ocean Topography mission.


Seasat inspired a whole generation of scientists. "I decided to take a job offer at JPL fresh out of graduate school because I was told that the future of oceanography is in satellite oceanography and the future of satellite oceanography will begin with Seasat at JPL," said JPL oceanographer Tim Liu. "I did not plan to stay forever, but I have now been here more than three decades."


Since Seasat, advanced ocean altimeters on the NASA/European Topex/Poseidon and Jason missions have been making precise measurements of sea surface height used to study climate phenomena such as El Niño and La Niña. The newest Jason mission, Jason-3, is scheduled to launch in 2015 to continue the 20-plus-year climate data record. Satellite altimetry has been used to improve weather and climate models, ship routing, marine mammal studies, fisheries management and offshore operations.
Seasat's scatterometer gave us our first real-time global map of the speed and direction of ocean winds, which drive waves and currents and are the major link between the ocean and atmosphere. A scatterometer is a microwave radar sensor used to measure the reflection or scattering effect produced while scanning the surface of Earth from an aircraft or a satellite. The technology was later used on JPL's NASA Scatterometer, Quikscat spacecraft, SeaWinds instrument on Japan's Midori 2 spacecraft and the OSCAT instrument on India's Oceansat-2. It will also be used on JPL's ISS-RapidScat instrument, launching to the International Space Station in the spring of 2014. Data from these scatterometers, including three scatterometers launched by the European Space Agency, help forecasters predict hurricanes, tropical storms and El Ninos.


Seasat's microwave radiometer, which subsequently flew on NASA's Nimbus-7 satellite, led to numerous successful radiometer instruments and missions used for oceanography, weather and climate research. Radiometers measure particular wavelengths of microwave energy. The Seasat radiometer's heritage includes the Special Sensor Microwave Imager instruments launched on United States Air Force Defense Meteorological Satellite Program satellites, the joint NASA/Japanese Aerospace Exploration Agency (JAXA) Tropical Rainfall Measuring Mission microwave imager, the Advanced Microwave Scanning Radiometer (AMSR)-E that flew aboard NASA's Aqua spacecraft, JAXA's current AMSR-2 instrument, and numerous other radiometers launched by Europe, China and India. The radiometer, scatterometer and SAR for NASA's Soil Moisture Active Passive mission to measure global soil moisture, launching in 2014, also draw upon Seasat's heritage.


By simultaneously flying a radiometer with a radar altimeter, Seasat demonstrated the benefit of using radiometer measurements of water vapor to correct altimeter measurements of sea surface height. Water vapor affects the accuracy of altimeter measurements by delaying the time it takes for the altimeter's signals to make their round trip to the ocean surface and back. This technique has been used on all subsequent NASA/European satellite altimetry missions.


Seasat's oceanographic mission also studied sea ice and its role in controlling Earth's climate. Its SAR provided the first high-resolution images of sea ice, measuring its movement, deformation and age. Today, SAR and scatterometers are also used to monitor Earth's ice from space.


"It's hard to imagine where we would be without the radiometer pioneered on Seasat, but certainly much further behind in critical Earth observations than we are now," said Gary Lagerloef of Earth & Space Research, Seattle, principal investigator of NASA's Aquarius mission to map ocean surface salinity. The Aquarius radiometer and scatterometer also trace their heritage back to Seasat.


Seasat's SAR monitored the global surface wave field and revealed many oceanic- and atmospheric-related phenomena, from current boundaries to eddies and internal waves.


Beyond the ocean, Seasat's SAR provided spectacular images of Earth's land surfaces and geology. Seasat data were used to pioneer radar interferometry, which uses microwave energy pulses sent from sensors on satellites or aircraft to the ground to detect land surface changes such as those created by earthquakes, and measure land surface topography. Three JPL Shuttle Imaging Radar experiments flew on the Space Shuttle in the 1980s/1990s. In 2000, JPL's Shuttle Radar Topography Mission used the technology to create the world's most detailed topographic measurements of more than 80 percent of Earth's land surface. Today, the technology is being used on JPL's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) airborne imaging radar system for a wide variety of Earth studies. Among the international SAR missions with heritages tracing to Seasat are the Japanese Earth Resources Satellite 1 and Advanced Land Observing System 1, the Canadian/U.S. Radarsat 1 and the European Space Agency's Remote Sensing Satellites. The technology will also be used on NASA's planned Surface Water and Ocean Topography mission, planned for launch in 2020.


Paul Rosen, JPL project scientist for a future NASA L-band SAR spacecraft currently under study, said Seasat's demonstration of spaceborne repeat-pass radar interferometry to measure minute Earth surface motions has led to a new field of space geodetic imaging and forms the basis for his new mission.


"Together with international L-band SAR sensors, we have the opportunity in the next five years to create a 40-year observation record of land-use change where overlapping observations exist," Rosen said. "These time-lapse images of change will provide fascinating insights into urban growth, agricultural patterns and other signs of human-induced changes over decades and climate change in the polar regions."


Beyond Earth, Seasat technology was used on JPL's Magellan mission, which mapped 99 percent of the previously hidden surface of Venus, and the Titan radar onboard the JPL-built and -managed Cassini orbiter to Saturn.


Seasat was managed by JPL for NASA, with significant participation from NASA's Goddard Space Flight Center, Greenbelt, Md.; NASA's Wallops Flight Facility, Wallops Island, Va.; NASA's Langley Research Center, Hampton, Va.; NASA's Glenn Research Center, Cleveland, Ohio; Johns Hopkins University Applied Physics Laboratory, Laurel, Md.; Lockheed Missiles and Space Systems, Sunnyvale, Calif.; and NOAA, Washington, D.C.


For more on Seasat, visit: http://podaac.jpl.nasa.gov/SeaSAT and http://www.jpl.nasa.gov/multimedia/seasat/intro.html . JPL is a division of the California Institute of Technology, Pasadena.

Alan Buis

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-0474

alan.buis@jpl.nasa.gov


2013-208
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NASA's Voyager 1 Explores Final Frontier of Our 'Solar Bubble'

NASA's Voyager 1 Explores Final Frontier of Our 'Solar Bubble':

This artist's concept shows NASA's two Voyager spacecraft exploring a turbulent region of space known as the heliosheath, the outer shell of the bubble of charged particles around our sun
This artist's concept shows NASA's two Voyager spacecraft exploring a turbulent region of space known as the heliosheath, the outer shell of the bubble of charged particles around our sun. Image Credit: NASA/JPL-Caltech
› Larger view

June 27, 2013

PASADENA, Calif. -- Data from Voyager 1, now more than 11 billion miles (18 billion kilometers) from the sun, suggest the spacecraft is closer to becoming the first human-made object to reach interstellar space.


Research using Voyager 1 data and published in the journal Science today provides new detail on the last region the spacecraft will cross before it leaves the heliosphere, or the bubble around our sun, and enters interstellar space. Three papers describe how Voyager 1's entry into a region called the magnetic highway resulted in simultaneous observations of the highest rate so far of charged particles from outside heliosphere and the disappearance of charged particles from inside the heliosphere.


Scientists have seen two of the three signs of interstellar arrival they expected to see: charged particles disappearing as they zoom out along the solar magnetic field, and cosmic rays from far outside zooming in. Scientists have not yet seen the third sign, an abrupt change in the direction of the magnetic field, which would indicate the presence of the interstellar magnetic field.


"This strange, last region before interstellar space is coming into focus, thanks to Voyager 1, humankind's most distant scout," said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena. "If you looked at the cosmic ray and energetic particle data in isolation, you might think Voyager had reached interstellar space, but the team feels Voyager 1 has not yet gotten there because we are still within the domain of the sun's magnetic field."


Scientists do not know exactly how far Voyager 1 has to go to reach interstellar space. They estimate it could take several more months, or even years, to get there. The heliosphere extends at least 8 billion miles (13 billion kilometers) beyond all the planets in our solar system. It is dominated by the sun's magnetic field and an ionized wind expanding outward from the sun. Outside the heliosphere, interstellar space is filled with matter from other stars and the magnetic field present in the nearby region of the Milky Way.


Voyager 1 and its twin spacecraft, Voyager 2, were launched in 1977. They toured Jupiter, Saturn, Uranus and Neptune before embarking on their interstellar mission in 1990. They now aim to leave the heliosphere. Measuring the size of the heliosphere is part of the Voyagers' mission.


The Science papers focus on observations made from May to September 2012 by Voyager 1's cosmic ray, low-energy charged particle and magnetometer instruments, with some additional charged particle data obtained through April of this year.


Voyager 2 is about 9 billion miles (15 billion kilometers) from the sun and still inside the heliosphere. Voyager 1 was about 11 billion miles (18 billion kilometers) from the sun Aug. 25 when it reached the magnetic highway, also known as the depletion region, and a connection to interstellar space. This region allows charged particles to travel into and out of the heliosphere along a smooth magnetic field line, instead of bouncing around in all directions as if trapped on local roads. For the first time in this region, scientists could detect low-energy cosmic rays that originate from dying stars.


"We saw a dramatic and rapid disappearance of the solar-originating particles. They decreased in intensity by more than 1,000 times, as if there was a huge vacuum pump at the entrance ramp onto the magnetic highway," said Stamatios Krimigis, the low-energy charged particle instrument's principal investigator at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "We have never witnessed such a decrease before, except when Voyager 1 exited the giant magnetosphere of Jupiter, some 34 years ago."


Other charged particle behavior observed by Voyager 1 also indicates the spacecraft still is in a region of transition to the interstellar medium. While crossing into the new region, the charged particles originating from the heliosphere that decreased most quickly were those shooting straightest along solar magnetic field lines. Particles moving perpendicular to the magnetic field did not decrease as quickly. However, cosmic rays moving along the field lines in the magnetic highway region were somewhat more populous than those moving perpendicular to the field. In interstellar space, the direction of the moving charged particles is not expected to matter.


In the span of about 24 hours, the magnetic field originating from the sun also began piling up, like cars backed up on a freeway exit ramp. But scientists were able to quantify that the magnetic field barely changed direction -- by no more than 2 degrees.


"A day made such a difference in this region with the magnetic field suddenly doubling and becoming extraordinarily smooth," said Leonard Burlaga, the lead author of one of the papers, and based at NASA's Goddard Space Flight Center in Greenbelt, Md. "But since there was no significant change in the magnetic field direction, we're still observing the field lines originating at the sun."


NASA's Jet Propulsion Laboratory, in Pasadena, Calif., built and operates the Voyager spacecraft. California Institute of Technology in Pasadena manages JPL for NASA. The Voyager missions are a part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate at NASA Headquarters in Washington.


For more information about the Voyager spacecraft mission, visit: http://www.nasa.gov/voyager and
http://voyager.jpl.nasa.gov .

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Steve Cole 202-358-0918

NASA Headquarters, Washington

stephen.e.cole@nasa.gov


2013-209
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NASA Decommissions Its Galaxy Hunter Spacecraft

NASA Decommissions Its Galaxy Hunter Spacecraft:

This image from NASA's Galaxy Evolution Explorer (GALEX) shows Messier 94, also known as NGC 4736, in ultraviolet light
This image from NASA's Galaxy Evolution Explorer (GALEX) shows Messier 94, also known as NGC 4736, in ultraviolet light. It is located 17 million light-years away in the constellation Canes Venatici. Image credit: NASA/JPL-Caltech
› Full image and caption

June 28, 2013

PASADENA, Calif. -- NASA has turned off its Galaxy Evolution Explorer (GALEX) after a decade of operations in which the venerable space telescope used its ultraviolet vision to study hundreds of millions of galaxies across 10 billion years of cosmic time.


"GALEX is a remarkable accomplishment," said Jeff Hayes, NASA's GALEX program executive in Washington. "This small Explorer mission has mapped and studied galaxies in the ultraviolet, light we cannot see with our own eyes, across most of the sky."


Operators at Orbital Sciences Corporation in Dulles, Va., sent the signal to decommission GALEX at 12:09 p.m. PDT (3:09 p.m. EDT) Friday, June 28. The spacecraft will remain in orbit for at least 65 years, then fall to Earth and burn up upon re-entering the atmosphere. GALEX met its prime objectives and the mission was extended three times before being cancelled.


Highlights from the mission's decade of sky scans include:


-- Discovering a gargantuan, comet-like tail behind a speeding star called Mira.

-- Catching a black hole "red-handed" as it munched on a star.

-- Finding giant rings of new stars around old, dead galaxies.

-- Independently confirming the nature of dark energy.

-- Discovering a missing link in galaxy evolution -- the teenage galaxies transitioning from young to old.


The mission also captured a dazzling collection of snapshots, showing everything from ghostly nebulas to a spiral galaxy with huge, spidery arms.


In a first-of-a-kind move for NASA, the agency in May 2012 loaned GALEX to the California Institute of Technology in Pasadena, which used private funds to continue operating the satellite while NASA retained ownership. Since then, investigators from around the world have used GALEX to study everything from stars in our own Milky Way galaxy to hundreds of thousands of galaxies 5 billion light-years away.


In the space telescope's last year, it scanned across large patches of sky, including the bustling, bright center of our Milky Way. The telescope spent time staring at certain areas of the sky, finding exploded stars, called supernovae, and monitoring how objects, such as the centers of active galaxies, change over time. GALEX also scanned the sky for massive, feeding black holes and shock waves from early supernova explosions.


"In the last few years, GALEX studied objects we never thought we'd be able to observe, from the Magellanic Clouds to bright nebulae and supernova remnants in the galactic plane," said David Schiminovich of Columbia University, N.Y., N.Y, a longtime GALEX team member who led science operations over the past year. "Some of its most beautiful and scientifically compelling images are part of this last observation cycle."


Data from the last year of the mission will be made public in the coming year.


"GALEX, the mission, may be over, but its science discoveries will keep on going," said Kerry Erickson, the mission's project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif.


A slideshow showing some of the popular GALEX images is online at: http://go.nasa.gov/17xAVDd


JPL managed the GALEX mission and built the science instrument. The mission's principal investigator, Chris Martin, is at Caltech. NASA's Goddard Space Flight Center in Greenbelt, Md., developed the mission under the Explorers Program it manages. Researchers sponsored by Yonsei University in South Korea and the Centre National d'Etudes Spatiales (CNES) in France collaborated on the mission. Caltech manages JPL for NASA.


Graphics and additional information about the Galaxy Evolution Explorer are online at: http://www.nasa.gov/galex

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

alan.d.buis@jpl.nasa.gov


J.D. Harrington 202-358-5241

Headquarters, Washington

j.d.harrington@nasa.gov


2013-211
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NASA Decommissions Its Galaxy Hunter Spacecraft

NASA Decommissions Its Galaxy Hunter Spacecraft:

This image from NASA's Galaxy Evolution Explorer (GALEX) shows Messier 94, also known as NGC 4736, in ultraviolet light
This image from NASA's Galaxy Evolution Explorer (GALEX) shows Messier 94, also known as NGC 4736, in ultraviolet light. It is located 17 million light-years away in the constellation Canes Venatici. Image credit: NASA/JPL-Caltech
› Full image and caption

June 28, 2013

PASADENA, Calif. -- NASA has turned off its Galaxy Evolution Explorer (GALEX) after a decade of operations in which the venerable space telescope used its ultraviolet vision to study hundreds of millions of galaxies across 10 billion years of cosmic time.


"GALEX is a remarkable accomplishment," said Jeff Hayes, NASA's GALEX program executive in Washington. "This small Explorer mission has mapped and studied galaxies in the ultraviolet, light we cannot see with our own eyes, across most of the sky."


Operators at Orbital Sciences Corporation in Dulles, Va., sent the signal to decommission GALEX at 12:09 p.m. PDT (3:09 p.m. EDT) Friday, June 28. The spacecraft will remain in orbit for at least 65 years, then fall to Earth and burn up upon re-entering the atmosphere. GALEX met its prime objectives and the mission was extended three times before being cancelled.


Highlights from the mission's decade of sky scans include:


-- Discovering a gargantuan, comet-like tail behind a speeding star called Mira.

-- Catching a black hole "red-handed" as it munched on a star.

-- Finding giant rings of new stars around old, dead galaxies.

-- Independently confirming the nature of dark energy.

-- Discovering a missing link in galaxy evolution -- the teenage galaxies transitioning from young to old.


The mission also captured a dazzling collection of snapshots, showing everything from ghostly nebulas to a spiral galaxy with huge, spidery arms.


In a first-of-a-kind move for NASA, the agency in May 2012 loaned GALEX to the California Institute of Technology in Pasadena, which used private funds to continue operating the satellite while NASA retained ownership. Since then, investigators from around the world have used GALEX to study everything from stars in our own Milky Way galaxy to hundreds of thousands of galaxies 5 billion light-years away.


In the space telescope's last year, it scanned across large patches of sky, including the bustling, bright center of our Milky Way. The telescope spent time staring at certain areas of the sky, finding exploded stars, called supernovae, and monitoring how objects, such as the centers of active galaxies, change over time. GALEX also scanned the sky for massive, feeding black holes and shock waves from early supernova explosions.


"In the last few years, GALEX studied objects we never thought we'd be able to observe, from the Magellanic Clouds to bright nebulae and supernova remnants in the galactic plane," said David Schiminovich of Columbia University, N.Y., N.Y, a longtime GALEX team member who led science operations over the past year. "Some of its most beautiful and scientifically compelling images are part of this last observation cycle."


Data from the last year of the mission will be made public in the coming year.


"GALEX, the mission, may be over, but its science discoveries will keep on going," said Kerry Erickson, the mission's project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif.


A slideshow showing some of the popular GALEX images is online at: http://go.nasa.gov/17xAVDd


JPL managed the GALEX mission and built the science instrument. The mission's principal investigator, Chris Martin, is at Caltech. NASA's Goddard Space Flight Center in Greenbelt, Md., developed the mission under the Explorers Program it manages. Researchers sponsored by Yonsei University in South Korea and the Centre National d'Etudes Spatiales (CNES) in France collaborated on the mission. Caltech manages JPL for NASA.


Graphics and additional information about the Galaxy Evolution Explorer are online at: http://www.nasa.gov/galex

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

alan.d.buis@jpl.nasa.gov


J.D. Harrington 202-358-5241

Headquarters, Washington

j.d.harrington@nasa.gov


2013-211
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Radio Bursts Discovered From Beyond our Galaxy

Radio Bursts Discovered From Beyond our Galaxy:

Parkes Telescope
This image shows the Parkes telescope in Australia, part of the
Commonwealth Scientific and Industrial Research
Organization. Researchers, including a team member from NASA's Jet
Propulsion Laboratory in Pasadena, used the telescope to detect the first
population of radio bursts known to originate from beyond our galaxy.
Image courtesy Shaun Amy
› Larger image

July 08, 2013

Astronomers, including a team member from NASA's Jet Propulsion Laboratory in Pasadena, Calif., have detected the first population of radio bursts known to originate from galaxies beyond our own Milky Way. The sources of the light bursts are unknown, but cataclysmic events, such as merging or exploding stars, are likely the triggers.


A radio burst is a quick surge of light from a point on the sky, made up of longer wavelengths in the radio portion of the light spectrum. A single radio burst was detected about six years ago, but researchers were unclear about whether it came from within or beyond our galaxy.


The new radio-burst detections -- four in total -- are from billions of light-years away, erasing any doubt that the phenomenon is real. The discovery, described in the July 4 issue of the journal Science, comes from an international team that used the Parkes Observatory in Australia.


"Short radio bursts are really tricky to identify," explained Sarah Burke Spolaor of JPL. "Our team had to search 11 months of data covering a large sky area to find them."


Spolaor developed the software used to seek single pulses in the radio data and pick out genuine signals from local interference sources -- such as cell phones, spark plugs and aircraft. This amounted to an enormous and complex computational task.


Dan Thornton, lead author of the new study from England's University of Manchester and Australia's Commonwealth Scientific and Industrial Research Organization, said, "The radio bursts last for just a few milliseconds and the farthest one that we detected was 11 billion light-years away."


The findings open the door to studying an entirely new class of eruptive cosmic events and can also help with cosmology mysteries, for example, about the nature of matter in the universe.


Our sky is full of flares and bursts of varying natures. For instance, gamma-ray bursts are thought to occur when stars collapse into black holes. They are routinely detected by a network of telescopes on the ground and in space, including NASA's Swift and Fermi. When one telescope in the network detects a burst, it can notify others to quickly slew to the target for coordinated observations.


The newfound radio bursts, while likely of a different origin than gamma-ray bursts, also consist of light waves generated by powerful events happening at great distances. Researchers would like to develop systems similar to the gamma-ray burst networks of telescopes to follow up quickly on radio bursts, but this is more challenging because radio waves are slowed by gas in space. Time is needed to process the radio observations and tease out the short-lived bursts.


On the other hand, the fact that radio waves are impeded as they travel through space to reach us offers benefits. By studying how the radio waves have been slowed, scientists can better understand baryonic matter, the material that gets in the way. Baryonic matter is what makes up people and planets and everything you see. The rest of the universe consists of mysterious substances called dark matter and dark energy.


Exactly what is triggering the release of the radio waves is unknown. Theories include colliding neutron stars or black holes; evaporating black holes; and stellar explosions called supernovae. The new data do not fit nicely with any of these scenarios, leaving the scientists perplexed.


Further scans for radio bursts using the Parkes Observatory are ongoing. Researchers are also using other telescopes to search for and characterize these events. For instance, the V-Fastr project, developed in part at JPL, is currently running on the National Radio Astronomy Observatory's Very Long Baseline Array, an international network of telescopes. It will enable scientists to localize a burst's origin to a precise location in a distant host galaxy.


Other institutions participating in this study are: Max-Planck Institute for Radio Astronomy, Germany; the INAF-Cagliari Astronomical Observatory and the Cagliari Observatory and University, Italy; Swinburne University of Technology, the Commonwealth Scientific and Industrial Research Organization, the Australian Research Council Centre of Excellence for All-Sky Astrophysics and Curtin University, all in Australia; and West Virginia University, Morgantown.


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

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-216
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NASA Discusses Mars 2020 Plans in July 9 Teleconference

NASA Discusses Mars 2020 Plans in July 9 Teleconference:

Global view of Mars
This global view of Mars is composed of about 100 Viking Orbiter images. Image credit: NASA/JPL-Caltech
› Larger image

July 08, 2013

WASHINGTON -- NASA will host a media teleconference at noon PDT (3 p.m. EDT) on Tuesday, July 9 to provide details about a report that will help define science objectives for the agency's next Mars rover.


The report, prepared by the Mars 2020 Science Definition Team (SDT) NASA appointed in January, is an early, crucial step in developing the mission and the rover's prime science objectives.


The teleconference participants are:


-- John Grunsfeld, NASA's associate administrator for science, Washington

-- Jim Green, director, Planetary Science Division, NASA Headquarters, Washington

-- Jack Mustard, SDT chair and professor of geological sciences, Brown University, Providence. R.I.

-- Lindy Elkins-Tanton, SDT member and director of the Carnegie Institution for Science's Department of Terrestrial Magnetism, Washington

The Mars 2020 Science Definition Team report will be posted an hour before the teleconference at:
http://mars.jpl.nasa.gov/m2020/ .


Audio of the teleconference will be streamed live at: http://www.nasa.gov/newsaudio . The telecon and graphics will also be streamed on the Web at: http://www.ustream.tv/nasajpl2 .
Graphics for the teleconference will be posted online at: http://www.nasa.gov/mars/telecon20130709

Guy Webster 818-354-6278

Jet Propulsion Laboratory, Pasadena, Calif.

guy.webster@jpl.nasa.gov

Dwayne Brown 202-358-1726

Headquarters, Washington

dwayne.c.brown@nasa.gov
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Long-Running Jason-1 Ocean Satellite Takes Final Bow

Long-Running Jason-1 Ocean Satellite Takes Final Bow:

Artist's concept of the joint NASA/CNES Jason-1 ocean altimetry satellite
Artist's concept of the joint NASA/CNES Jason-1 ocean altimetry satellite. During its 11-1/2-year life, Jason-1 helped create a 20-plus-year climate record of global ocean surface topography, providing new insights into ocean circulation, tracking our rising seas and enabling more accurate weather, ocean and climate forecasts. Image credit: NASA/JPL-Caltech
› Larger image


July 03, 2013

PASADENA, Calif. - The curtain has come down on a superstar of the satellite oceanography world that played the "Great Blue Way" of the world's ocean for 11-1/2 years. The successful joint NASA and Centre National d'Etudes Spatiales (CNES) Jason-1 ocean altimetry satellite was decommissioned this week following the loss of its last remaining transmitter.


Launched Dec. 7, 2001, and designed to last three to five years, Jason-1 helped create a revolutionary 20-plus-year climate data record of global ocean surface topography that began in 1992 with the launch of the NASA/CNES Topex/Poseidon satellite. For more than 53,500 orbits of our planet, Jason-1 precisely mapped sea level, wind speed and wave height for more than 95 percent of Earth's ice-free ocean every 10 days. The mission provided new insights into ocean circulation, tracked our rising seas and enabled more accurate weather, ocean and climate forecasts.


"Jason-1 has been a resounding scientific, technical and international success," said John Grunsfeld, associate administrator of NASA's Science Mission Directorate in Washington. "The mission met all of its requirements, performed an extended mission and demonstrated how a long-term climate data record should be established from successively launched satellites. Since launch, it has charted nearly 1.6 inches (4 centimeters) of rise in global sea levels, a critical measure of climate change and a direct result of global warming. The Jason satellite series provides the most accurate measure of this impact, which is felt all over the globe."


During parts of its mission, Jason-1 flew in carefully coordinated orbits with both its predecessor Topex/Poseidon and its successor, the Ocean Surface Topography Mission/Jason-2, launched in 2008. These coordinated orbit periods, which lasted about three years each, cross-calibrated the satellites, making possible a 20-plus-year unbroken climate record of sea level change. These coordination periods also doubled data coverage.


Combined with data from the European Space Agency's Envisat mission, which also measured sea level from space, these data allow scientists to study smaller-scale ocean circulation phenomena, such as coastal tides, ocean eddies, currents and fronts. These small-scale features are thought to be responsible for transporting and mixing heat and other properties, such as nutrients and dissolved carbon dioxide, within the ocean.


"Jason-1 was an exemplary and multi-faceted altimeter mission and contributed so much to so many scientific disciplines," said Jean-Yves Le Gall, CNES president in Paris. "Not only did Jason-1 extend the precise climate record established by Topex/Poseidon, it made invaluable observations for mesoscale ocean studies on its second, interleaved orbit. Even from its 'graveyard' orbit, Jason-1 continued to make unprecedented new observations of the Earth's gravity field, with precise measurements right till the end."


The in-orbit Jason-2 mission, operated by the meteorological agencies of the United States and Europe (the National Oceanic and Atmospheric Administration and EUMETSAT, respectively) in collaboration with NASA and CNES, is in good health and continues to collect science and operational data. This same U.S./European team is preparing to launch the next satellite in the series, Jason-3, in March 2015.


Contact was lost with the Jason-1 satellite on June 21 when it was out of visibility of ground stations. At the time of the last contact, Jason-1 and its instruments were healthy, with no indications of any alarms or anomalies. Subsequent attempts to re-establish spacecraft communications from U.S. and French ground stations were unsuccessful. Extensive engineering operations undertaken to recover downlink communications also were unsuccessful.


After consultation with the spacecraft and transmitter manufacturers, it was determined a non-recoverable failure with the last remaining transmitter on Jason-1 was the cause of the loss of contact. The spacecraft's other transmitter experienced a permanent failure in September 2005. There now is no remaining capability to retrieve data from the Jason-1 spacecraft.


On July 1, mission controllers commanded Jason-1 into a safe hold state that reinitialized the satellite. After making several more unsuccessful attempts to locate a signal, mission managers at CNES and NASA decided to proceed with decommissioning Jason-1. The satellite was then commanded to turn off its magnetometer and reaction wheels. Without these attitude control systems, Jason-1 and its solar panels will slowly drift away from pointing at the sun and its batteries will discharge, leaving it totally inert within the next 90 days. The spacecraft will not reenter Earth's atmosphere for at least 1,000 years.


"Like its predecessor Topex/Poseidon, Jason-1 provided one of the most comprehensive pictures of changes in the tropical Pacific Ocean, including the comings and goings of El Nino and La Nina events," said Lee-Lueng Fu, Jason-1 project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "These Pacific Ocean climate cycles are responsible for major shifts in sea level, ocean temperatures and rainfall every two to five years and can sometimes be so large that worldwide weather patterns are affected. Jason-1 data have been instrumental in monitoring and predicting these ever-changing cycles."


In the spring of 2012, based on concern over the limited redundancy of Jason-1's aging control systems, NASA and CNES moved the satellite into its planned final "graveyard" orbit, depleted its extra fuel and reconfigured the mission to make observations that will improve our knowledge of Earth's gravity field over the ocean, in addition to delivering its oceanographic data products.


The first full 406-day marine gravity mission was completed on June 17. The resulting data have already led to the discovery of numerous small seamounts, which are underwater mountains that rise above the deep-sea floor. The data also have significantly increased the resolution of Earth's gravity field over the ocean, while increasing our knowledge of ocean bathymetry, which is the underwater depth of the ocean floor.


JPL manages the U.S. portion of the Jason-1 mission for NASA's Science Mission Directorate. CNES manages the French portion of the mission.


For more information on Jason-1, visit: http://sealevel.jpl.nasa.gov and http://www.aviso.oceanobs.com .


The California Institute of Technology in Pasadena manages JPL for NASA.

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

Alan.buis@jpl.nasa.gov


Steve Cole 202-358-0918

NASA Headquarters, Washington

Stephen.e.cole@nasa.gov


Julien Watelet 011-33-6-88-06-11-48

Centre National d'Etudes Spatiales, Paris, France

Julien.watelet@cnes.fr


2013-213
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NASA's OPALS to Beam Data From Space Via Laser

NASA's OPALS to Beam Data From Space Via Laser:

This artist's concept shows how the Optical Payload for Lasercomm Science (OPALS) laser will beam data to Earth from the International Space Station.
This artist's concept shows how the Optical Payload for Lasercomm Science (OPALS) laser will beam data to Earth from the International Space Station. Credit: NASA.
› Larger image

July 11, 2013

PASADENA, Calif. -- NASA will use the International Space Station to test a new communications technology that could dramatically improve spacecraft communications, enhance commercial missions and strengthen transmission of scientific data.


The Optical Payload for Lasercomm Science (OPALS), an optical technology demonstration experiment, could improve NASA's data rates for communications with future spacecraft by a factor of 10 to 100. OPALS has arrived at NASA's Kennedy Space Center in Florida from the agency's Jet Propulsion Laboratory in Pasadena, Calif. It is scheduled to launch to the space station later this year aboard a SpaceX Dragon commercial resupply capsule on the company's Falcon 9 rocket.


"OPALS represents a tangible stepping stone for laser communications, and the International Space Station is a great platform for an experiment like this," said Michael Kokorowski, OPALS project manager at JPL. "Future operational laser communication systems will have the ability to transmit more data from spacecraft down to the ground than they currently do, mitigating a significant bottleneck for scientific investigations and commercial ventures."


OPALS will be mounted on the outside of the International Space Station and communicate with a ground station in Wrightwood, Calif., a mountain town near Los Angeles.


"It's like aiming a laser pointer continuously for two minutes at a dot the diameter of a human hair from 30 feet away while you're walking," explained OPALS systems engineer Bogdan Oaida of JPL.


The OPALS instrument was built at JPL and is slated to fly on the Dragon capsule in late 2013. The mission is expected to run 90 days after installation on the station.


The OPALS Project Office is based at JPL, a division of the California Institute of Technology in Pasadena.


For more information about OPALS, visit: http://go.nasa.gov/10MMPDO .


For more information about the International Space Station, visit: http://www.nasa.gov/station .

Stephanie L. Smith 818-393-5464

Jet Propulsion Laboratory, Pasadena, Calif.

slsmith@jpl.nasa.gov


Joshua Buck 202-358-1100

NASA Headquarters, Washington

jbuck@nasa.gov


2013-218
Posted by Nelio Inacio at 8:01 AM 0 comments
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