Wednesday, July 23, 2014

Littlest Continent Had Biggest Role in Sea Level Drop

Littlest Continent Had Biggest Role in Sea Level Drop:

Australia, combined with the continent's soils and unique topography
Changes in Australia's mass as reported by data from NASA's Gravity Recovery and Climate Experiment (GRACE) satellites from June 2010 to February 2011. Areas in greens and blues depict the greatest increases in mass, caused by excessive precipitation. The contour lines represent various land surface elevations. A new study co-authored and co-funded by NASA finds extensive flooding in Australia, combined with the continent's soils and unique topography, were the biggest contributors to the drop in global sea level observed in 2010 and 2011. Credit: NCAR/NASA/JPL-Caltech

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August 19, 2013

A unique and complex set of circumstances came together over Australia from 2010 to 2011 to cause Earth's smallest continent to be the biggest contributor to the observed drop in global sea level rise during that time, finds a new study co-authored and co-funded by NASA.


In 2011, scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the University of Colorado at Boulder reported that between early 2010 and summer 2011, global sea level fell sharply, by about a quarter of an inch, or half a centimeter. Using data from the NASA/German Aerospace Center's Gravity Recovery and Climate Experiment (GRACE) spacecraft, they showed that the drop was caused by the very strong La Nina that began in late 2010. That La Nina changed rainfall patterns all over our planet, moving huge amounts of Earth's water from the ocean to the continents. The phenomenon was short-lived, however.


By mid-2012, global mean sea level had resumed its long-term mean annual rise of 0.13 inches (3.2 millimeters) per year (see http://www.jpl.nasa.gov/news/news.php?release=2012-362 ).


But analyses of the historical record showed that past La Nina events only rarely accompanied such a pronounced drop in sea level. So what made this particular La Nina unique?


To better understand this phenomenon, scientists at the National Center for Atmospheric Research (NCAR) in Boulder, Colo.; JPL; and the University of Colorado at Boulder combined GRACE data with data from the Argo global array of 3,000 free-drifting floats and satellite altimeters (Jason-1, Jason-2 and Topex/Poseidon).


They found that three atmospheric patterns converged over the Indian and Pacific Oceans in 2010 and 2011 to drive excessive precipitation over Australia. On average, the continent received almost one foot (300 millimeters) of rain more than normal. The result was widespread flooding. The flooding was in large part prevented from running back into the ocean by Australia's dry soils and the mountain-ringed topography of the country's vast interior, called the Outback, leading to the measurable drop in the world's ocean levels.


"No other continent has this combination of atmospheric set-up and topography," said NCAR scientist John Fasullo, lead author of the study. "Only in Australia could the atmosphere carry such heavy tropical rains to such a large area, only to have those rains fail to make their way to the ocean."


Now that the atmospheric patterns have snapped back and more rain is falling over tropical oceans, the seas are rising again. In fact, with Australia in a major drought, they are rising faster than before. Since 2011, when the atmospheric patterns shifted out of their unusual combination, sea levels have been rising at a faster pace of about 0.4 inches (10 millimeters) per year.


The study, co-funded by NASA and the National Science Foundation, will be published next month in the journal Geophysical Research Letters.


For more information, read the full NCAR news release: http://www2.ucar.edu/atmosnews/news/10090/global-sea-level-rise-dampened-australia-floods .

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

alan.buis@jpl.nasa.gov


David Hosansky 303-497-8611

National Center for Atmospheric Research, Boulder, Colo.

hosansky@ucar.edu


2013-255
Posted by Nelio Inacio at 4:27 PM 0 comments

NASA Spacecraft Reactivated to Hunt for Asteroids

NASA Spacecraft Reactivated to Hunt for Asteroids:

Back to Hunt More Asteroids
This artist's concept shows the Wide-field Infrared Survey Explorer, or WISE spacecraft, in its orbit around Earth. In September of 2013, engineers will attempt to bring the mission out of hibernation to hunt for more asteroids and comets in a project called NEOWISE. Image credit: NASA/JPL-Caltech
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August 21, 2013

Probe Will Assist Agency in Search for Candidates to Explore


PASADENA, Calif. -- A NASA spacecraft that discovered and characterized tens of thousands of asteroids throughout the solar system before being placed in hibernation will return to service for three more years starting in September, assisting the agency in its effort to identify the population of potentially hazardous near-Earth objects, as well as those suitable for asteroid exploration missions.


The Wide-field Infrared Survey Explorer (WISE) will be revived next month with the goal of discovering and characterizing near-Earth objects (NEOs), space rocks that can be found orbiting within 28 million miles (45 million kilometers) from Earth's path around the sun. NASA anticipates WISE will use its 16-inch (40-centimeter) telescope and infrared cameras to discover about 150 previously unknown NEOs and characterize the size, albedo and thermal properties of about 2,000 others -- including some which could be candidates for the agency's recently announced asteroid initiative.


"The WISE mission achieved its mission's goals and as NEOWISE extended the science even further in its survey of asteroids. NASA is now extending that record of success, which will enhance our ability to find potentially hazardous asteroids, and support the new asteroid initiative," said John Grunsfeld, NASA's associate administrator for science in Washington. "Reactivating WISE is an excellent example of how we are leveraging existing capabilities across the agency to achieve our goal."


NASA's asteroid initiative will be the first mission to identify, capture and relocate an asteroid. It represents an unprecedented technological feat that will lead to new scientific discoveries and technological capabilities that will help protect our home planet. The asteroid initiative brings together the best of NASA's science, technology and human exploration efforts to achieve President Obama's goal of sending humans to an asteroid by 2025.


Launched in December 2009 to look for the glow of celestial heat sources from asteroids, stars and galaxies, WISE made about 7,500 images every day during its primary mission, from January 2010 to February 2011. As part of a project called NEOWISE, the spacecraft made the most accurate survey to date of NEOs. NASA turned most of WISE's electronics off when it completed its primary mission.


"The data collected by NEOWISE two years ago have proven to be a gold mine for the discovery and characterization of the NEO population," said Lindley Johnson, NASA's NEOWISE program executive in Washington. "It is important that we accumulate as much of this type of data as possible while the WISE spacecraft remains a viable asset."


Because asteroids reflect but do not emit visible light, infrared sensors are a powerful tool for discovering, cataloging and understanding the asteroid population. Depending on an object's reflectivity, or albedo, a small, light-colored space rock can look the same as a big, dark one. As a result, data collected with optical telescopes using visible light can be deceiving.


During 2010, NEOWISE observed about 158,000 rocky bodies out of approximately 600,000 known objects. Discoveries included 21 comets, more than 34,000 asteroids in the main belt between Mars and Jupiter, and 135 near-Earth objects.


The WISE prime mission was to scan the entire celestial sky in infrared light. It captured more than 2.7 million images in multiple infrared wavelengths and cataloged more than 560 million objects in space, ranging from galaxies faraway to asteroids and comets much closer to Earth.


"The team is ready and after a quick checkout, we're going to hit the ground running," said Amy Mainzer, NEOWISE principal investigator at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "NEOWISE not only gives us a better understanding of the asteroids and comets we study directly, but it will help us refine our concepts and mission operation plans for future, space-based near-Earth object cataloging missions."


JPL manages WISE for NASA's Science Mission Directorate at the agency's headquarters in Washington. The mission is part of NASA's Explorers Program, which NASA's Goddard Space Flight Center in Greenbelt, Md., manages. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colo., built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.


More information about NEOWISE is available online at: http://www.nasa.gov/wise and http://www.jpl.nasa.gov/wise/ .


For more information on the asteroid initiative, visit: http://www.nasa.gov/asteroidinitiative .

DC Agle 818-393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov


Dwayne Brown 202-358-1726

NASA Headquarters, Washington

Dwayne.c.brown@nasa.gov


2013-257
Posted by Nelio Inacio at 4:26 PM 0 comments

NASA Mars Rover Views Eclipse of the Sun by Phobos

NASA Mars Rover Views Eclipse of the Sun by Phobos:

Annular Eclipse of the Sun by Phobos, as Seen by Curiosity
This set of three images shows views three seconds apart as the larger of Mars' two moons, Phobos, passed directly in front of the sun as seen by NASA's Mars rover Curiosity. Curiosity photographed this annular, or ring, eclipse with the telephoto-lens camera of the rover's Mast Camera pair (right Mastcam) on Aug. 20, 2013, the 369th Martian day, or sol, of Curiosity's work on Mars. Image credit: NASA/JPL-Caltech/Malin Space Science Systems/Texas A&M Univ.
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August 28, 2013

PASADENA, Calif. - Images taken with a telephoto-lens camera on NASA's Mars rover Curiosity catch the larger of Mars' two moons, Phobos, passing directly in front of the sun -- the sharpest images of a solar eclipse ever taken at Mars.


Phobos does not fully cover the sun, as seen from the surface of Mars, so the solar eclipse is what's called a ring, or annular, type. A set of three frames from Curiosity's Mast Camera (Mastcam), taken three seconds apart as Phobos eclipsed the sun, is at http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA17356 .


The images are the first full-resolution frames downlinked to Earth from an Aug. 20, 2013, series. The series may later provide a movie of the eclipse. Curiosity paused during its drive that day to record the sky-watching images.


"This event occurred near noon at Curiosity's location, which put Phobos at its closest point to the rover, appearing larger against the sun than it would at other times of day," said Mark Lemmon of Texas A&M University, College Station, a co-investigator for use of Curiosity's Mastcam. "This is the closest to a total eclipse of the sun that you can have from Mars."


Observations of the Martian moons, Phobos and Deimos, by Curiosity and by the older, still-active Mars rover Opportunity are helping researchers get more precise knowledge of the moons' orbits. During the Aug. 20 observation, the position of Phobos crossing the sun was a mile or two (two or three kilometers) closer to the center of the sun's position than researchers anticipated.


Lemmon said, "This one is by far the most detailed image of any Martian lunar transit ever taken, and it is especially useful because it is annular. It was even closer to the sun's center than predicted, so we learned something."


NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, manages the Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington. JPL designed and built the project's Curiosity rover.


Malin Space Science Systems, San Diego, built and operates the Mastcam instrument and two other instruments on Curiosity.


More information about Curiosity is online at http://www.jpl.nasa.gov/msl , http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ . You can follow the mission on Facebook at http://www.facebook.com/marscuriosity and on Twitter at http://www.twitter.com/marscuriosity .

Guy Webster 818-354-6278

Jet Propulsion Laboratory, Pasadena, Calif.

guy.webster@jpl.nasa.gov


2013-263
Posted by Nelio Inacio at 4:25 PM 0 comments

NASA-Funded Scientists Detect Water on Moon's Surface that Hints at Water Below

NASA-Funded Scientists Detect Water on Moon's Surface that Hints at Water Below:

This image of the moon was generated by data collected by NASA's Moon Mineralogy Mapper
This image of the moon was generated by data collected by NASA's Moon Mineralogy Mapper on the Indian Space Research Organization's Chandrayaan-1 mission. It is a three-color composite of reflected near-infrared radiation from the sun, and illustrates the extent to which different materials are mapped across the side of the moon that faces Earth. Image credit: ISRO/NASA/JPL-Caltech/Brown Univ./USGS
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August 28, 2013

PASADENA - NASA-funded lunar research has yielded evidence of water locked in mineral grains on the surface of the moon from an unknown source deep beneath the surface. Using data from NASA's Moon Mineralogy Mapper (M3) instrument aboard the Indian Space Research Organization's Chandrayaan-1 spacecraft, scientists remotely detected magmatic water, or water that originates from deep within the moon's interior, on the surface of the moon.


The findings, published Aug. 25 in Nature Geoscience, represent the first detection of this form of water from lunar orbit. Earlier studies had shown the existence of magmatic water in lunar samples returned during NASA's Apollo program.


M3 imaged the lunar impact crater Bullialdus, which lies near the lunar equator. Scientists were interested in studying this area because they could better quantify the amount of water inside the rocks due to the crater's location and the type of rocks it held. The central peak of the crater is made up of a type of rock that forms deep within the lunar crust and mantle when magma is trapped underground.


"This rock, which normally resides deep beneath the surface, was excavated from the lunar depths by the impact that formed Bullialdus crater," said Rachel Klima, a planetary geologist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md.


"Compared to its surroundings, we found that the central portion of this crater contains a significant amount of hydroxyl - a molecule consisting of one oxygen atom and one hydrogen atom -- which is evidence that the rocks in this crater contain water that originated beneath the lunar surface," Klima said.


In 2009, M3 provided the first mineralogical map of the lunar surface and discovered water molecules in the polar regions of the moon. This water is thought to be a thin layer formed from solar wind hitting the moon's surface. Bullialdus crater is in a region with an unfavorable environment for solar wind to produce significant amounts of water on the surface.


"NASA missions like Lunar Prospector and the Lunar Crater Observation and Sensing Satellite and instruments like M3 have gathered crucial data that fundamentally changed our understanding of whether water exists on the surface of the moon," said S. Pete Worden, center director at NASA's Ames Research Center in Moffett Field, Calif. "Similarly, we hope that upcoming NASA missions such as the Lunar Atmosphere and Dust Environment Explorer, or LADEE, will change our understanding of the lunar sky."


The detection of internal water from orbit means scientists can begin to test some of the findings from sample studies in a broader context, including in regions that are far from where the Apollo sites are clustered on the near side of the moon. For many years, researchers believed that the rocks from the moon were bone-dry and any water detected in the Apollo samples had to be contamination from Earth.


"Now that we have detected water that is likely from the interior of the moon, we can start to compare this water with other characteristics of the lunar surface," said Klima. "This internal magmatic water also provides clues about the moon's volcanic processes and internal composition, which helps us address questions about how the moon formed, and how magmatic processes changed as it cooled."


The Moon Mineralogy Mapper was selected as a Mission of Opportunity through the NASA Discovery Program. NASA's Jet Propulsion Laboratory, Pasadena, Calif., designed and built the Moon Mineralogy Mapper and is home to its project manager, Mary White. JPL managed the program for NASA's Science Mission Directorate, Washington. Carle Pieters of Brown University, Providence, R.I., was the principal investigator. Joshua Cahill and David Lawrence of APL and Justin Hagerty of the U.S. Geological Survey's Astrogeology Science Center in Flagstaff, Ariz., co-authored the paper. The Chandrayaan-1 spacecraft was constructed, launched, and is operated by the Indian Space Research Organisation.


More information about Chandrayaan-1 visit: http://www.isro.org/Chandrayaan .

DC Agle 818-393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov


Dwayne Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov


2013-262
Posted by Nelio Inacio at 4:25 PM 0 comments

NuSTAR Delivers the X-Ray Goods

NuSTAR Delivers the X-Ray Goods:

Artist's concept of NuSTAR in orbit.
Artist's concept of NuSTAR on orbit. NuSTAR has a 10-m (30') 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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August 29, 2013

NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, is giving the wider astronomical community a first look at its unique X-ray images of the cosmos. The first batch of data from the black-hole hunting telescope is publicly available today, Aug. 29, via NASA's High Energy Astrophysics Science Archive Research Center, or HEASARC.


"We are pleased to present the world with NuSTAR's first look at the sky in high-energy X-rays with a true focusing telescope," said Fiona Harrison, the mission's principal investigator at the California Institute of Technology, Pasadena.


The images, taken from July to August 2012, shortly after the spacecraft launched, comprise an assortment of extreme objects, including black holes near and far. The more distant black holes are some of the most luminous objects in the universe, radiating X-rays as they ferociously consume surrounding gas. One type of black hole in the new batch of data is a blazar, which is an active, supermassive black hole pointing a jet toward Earth. Pairs of black holes called X-ray binaries, in which one partner feeds off the other, are also in the mix, along with the remnants of stellar blasts called supernovas.


The data set only contains complete observations. Data will be released at a later date for those targets still being observed.


"Astronomers can use these data to better understand the capabilities of NuSTAR and design future observing proposals. The first opportunity will be this fall, for joint observations with XMM-Newton," said Karl Forster of Caltech, who is leading the effort to package the data for the public.


The European Space Agency's XMM-Newton X-ray telescope, like NASA's Chandra X-ray Observatory, complements NuSTAR. While XMM-Newton and Chandra see lower-energy X-ray light, NuSTAR is the first telescope capable of focusing high-energy X-ray light, allowing for more detailed images than were possible before.


Astronomers can compare data sets from different missions using HEASARC, which gives them a broader understanding of an object of interest. NuSTAR's high-energy observations help scientists bridge a gap that existed previously in X-ray astronomy, and will lead to new revelations about the bizarre and energetic side of our universe.


Other NASA missions with data available via HEASARC include Chandra, Fermi, Swift, Cosmic Background Explorer (COBE), Wilkinson Microwave Anisotropy Probe (WMAP) and many more.


The HEASARC is a service of the Astrophysics Science Division at NASA's Goddard Space Flight Center in Greenbelt, Md., and the High Energy Astrophysics Division of the Smithsonian Astrophysics Observatory in Cambridge, Mass. HEASARC holdings include data obtained by NASA's high-energy astronomy missions observing in the extreme-ultraviolet, X-ray, and gamma-ray bands, as well as data from missions, balloons and ground-based facilities that have studied the relic cosmic microwave background. HEASARC is online at http://heasarc.gsfc.nasa.gov .


NuSTAR is a Small Explorer mission led by Caltech and managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., 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 (ASI) Science Data Center.


NuSTAR's mission operations center is at UC Berkeley, with ASI providing its equatorial ground station located at Malindi, Kenya. The mission's 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/ .

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

Alan.buis@jpl.nasa.gov


2013-264
Posted by Nelio Inacio at 4:24 PM 0 comments

NASA Study Eyes Soot's Role in 1800s Glacier Retreat

NASA Study Eyes Soot's Role in 1800s Glacier Retreat:

researchers and collaborators have combined historical records, ancient ice from cores in glaciers
NASA researchers and collaborators have combined historical records, ancient ice from cores in glaciers, modern air pollution studies and a model of glacier behavior to offer an explanation of why glaciers in the Alps started retreating in the late 19th century, despite cool temperatures and ample snowfall, which should have kept them growing. They find that soot from industrialization in Europe was deposited on the lower slopes of the glaciers, and that soot absorbed sunlight and accelerated melting. Although pollution sources today are not the same as in the 19th century, there is still enough pollution to make the air circulation patterns visible. This photo from summer 2012 looking south into the Bernese Alps shows how air pollution in the Alps tends to be confined to lower altitudes, concentrating the deposition of soot and dust on the lower slopes. At center left in the picture, a glacier can be seen extending from a high-altitude snow field, above the pollution layer, down into the valley where its lower reach is bathed in pollutants. Image credit: Peter Holy

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September 03, 2013

PASADENA, Calif. - A NASA-led team of scientists has uncovered strong evidence that soot from a rapidly industrializing Europe caused the abrupt retreat of mountain glaciers in the European Alps that began in the 1860s, a period often thought of as the end of the Little Ice Age.


The research, published Sept. 3 in the Proceedings of the National Academy of Sciences, may help resolve a longstanding scientific debate.


In the decades following the 1850s, Europe underwent an economic and atmospheric transformation spurred by industrialization. The use of coal to heat homes and power transportation and industry in Western Europe began in earnest, spewing huge quantities of black carbon and other dark particles into the atmosphere.


Black carbon is the strongest sunlight-absorbing atmospheric particle. When these particles settle on the snow blanketing glaciers, they darken the snow surface, speeding its melting and exposing the underlying glacier ice to sunlight and warmer spring and summer air earlier in the year. This diminishing of the snow cover earlier in each year causes the glacier ice to melt faster and retreat.


The Little Ice Age, loosely defined as a cooler period between the 14th and 19th centuries, was marked by an expansion of mountain glaciers and a drop in temperatures in Europe of nearly 1.8 degrees Fahrenheit (1 degree Celsius). But glacier records show that between 1860 and 1930, while temperatures continued to drop, large valley glaciers in the Alps abruptly retreated by an average of nearly 0.6 mile (1 kilometer) to lengths not seen in the previous few hundred years. Glaciologists and climatologists have struggled to reconcile this apparent conflict between climate and glacier records.


"Something was missing from the equation," said Thomas Painter, a snow and ice scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., who led the study. "Before now, most glaciologists believed the end of the Little Ice Age came in the mid-1800s when these glaciers retreated, and that the retreat was due to a natural climatic shift, distinct from the carbon dioxide-induced warming that came later in the 20th century. This result suggests that human influence on glaciers extends back to well before the industrial temperature increases."


To help the scientists understand what was driving the glacier retreat, Painter and his colleagues turned to history. The researchers studied data from ice cores drilled from high up on several European mountain glaciers to determine how much black carbon was in the atmosphere and snow when the Alps glaciers began to retreat. Using the levels of carbon particles trapped in the ice core layers, and taking into consideration modern observations of how pollutants are distributed in the Alps, they were able to estimate how much black carbon was deposited on glacial surfaces at lower elevations, where levels of black carbon tend to be highest.


The team then ran computer models of glacier behavior, starting with recorded weather conditions and adding the impact of the lower-elevation pollution. When this impact was included, the simulated glacier mass loss and timing finally were consistent with the historic record of glacial retreat, despite the cooling temperatures at that time.


"We must now look more closely at other regions on Earth, such as the Himalaya, to study the present-day impacts of black carbon on glaciers in these regions," said Georg Kaser, a study co-author from the University of Innsbruck, Austria, and lead author of the Working Group I Cryosphere chapter of the Intergovernmental Panel on Climate Change's upcoming Fifth Assessment Report.


"This study uncovers likely human fingerprints on our changing environment," said co-author Waleed Abdalati, director of the Cooperative Institute for Research and Environmental Sciences (CIRES) at the University of Colorado Boulder. "It's a reminder that the actions we take have far-reaching impacts on the environment in which we live."


CIRES is a joint institute of the university and the National Oceanic and Atmospheric Administration. Other institutions participating in the study include the University of Michigan - Ann Arbor and the University of California, Davis. The California Institute of Technology in Pasadena manages JPL for NASA.


For more information about NASA programs, visit: http://www.nasa.gov


Additional media contacts for this story: Katy Human, CIRES, 303-735-0196, Kathleen.human@colorado.edu ; Nicole Casal Moore, University of Michigan, 734-647-7087, ncmoore@umich.edu ; Stefan Hohenwarter, University of Innsbruck, 011-43-512-50732023, stefan.hohenwarter@uibk.ac.at ; Kat Kerlin, UC Davis, 530-752-7704, kekerlin@ucdavis.edu .

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


2013-267
Posted by Nelio Inacio at 4:24 PM 0 comments

Catching Black Holes on the Fly

Catching Black Holes on the Fly:

Black Holes Shine for NuSTAR
An optical color image of galaxies is seen here overlaid with X-ray data (magenta) from NASA's Nuclear Spectroscopic Telescope Array (NuSTAR). Image credit: NASA/JPL-Caltech
› Full image and caption


September 05, 2013

NASA's black-hole-hunter spacecraft, the Nuclear Spectroscopic Telescope Array, or NuSTAR, has "bagged" its first 10 supermassive black holes. The mission, which has a mast the length of a school bus, is the first telescope capable of focusing the highest-energy X-ray light into detailed pictures.


The new black-hole finds are the first of hundreds expected from the mission over the next two years. These gargantuan structures -- black holes surrounded by thick disks of gas -- lie at the hearts of distant galaxies between 0.3 and 11.4 billion light-years from Earth.


"We found the black holes serendipitously," explained David Alexander, a NuSTAR team member based in the Department of Physics at Durham University in England and lead author of a new study appearing Aug. 20 in the Astrophysical Journal. "We were looking at known targets and spotted the black holes in the background of the images."


Additional serendipitous finds such as these are expected for the mission. Along with the mission's more targeted surveys of selected patches of sky, the NuSTAR team plans to comb through hundreds of images taken by the telescope with the goal of finding black holes caught in the background.


Once the 10 black holes were identified, the researchers went through previous data taken by NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton satellite, two complementary space telescopes that see lower-energy X-ray light. The scientists found that the objects had been detected before. It wasn't until the NuSTAR observations, however, that they stood out as exceptional, warranting closer inspection.


By combining observations taken across the range of the X-ray spectrum, the astronomers hope to crack unsolved mysteries of black holes. For example, how many of them populate the universe?


"We are getting closer to solving a mystery that began in 1962," said Alexander. "Back then, astronomers had noted a diffuse X-ray glow in the background of our sky but were unsure of its origin. Now, we know that distant supermassive black holes are sources of this light, but we need NuSTAR to help further detect and understand the black hole populations."


This X-ray glow, called the cosmic X-ray background, peaks at the high-energy frequencies that NuSTAR is designed to see, so the mission is key to identifying what's producing the light. NuSTAR can also find the most hidden supermassive black holes, buried by thick walls of gas.


"The highest-energy X-rays can pass right through even significant amounts of dust and gas surrounding the active supermassive black holes," said Fiona Harrison, a study co-author and the mission's principal investigator at the California Institute of Technology, Pasadena.


Data from NASA's Wide-field Infrared Survey Explorer, or WISE, and Spitzer missions also provide missing pieces in the puzzle of black holes by weighing the mass of their host galaxies.


"Our early results show that the more distant supermassive black holes are encased in bigger galaxies," said Daniel Stern, a co-author of the study and the project scientist for NuSTAR at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "This is to be expected. Back when the universe was younger, there was a lot more action with bigger galaxies colliding, merging and growing."


Future observations will reveal more about the beastly happenings of black holes, near and far. In addition to hunting remote black holes, NuSTAR is also searching for other exotic objects within our Milky Way galaxy.


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 (ASI) Science Data Center.


NuSTAR's mission operations center is at UC Berkeley, with the ASI providing its equatorial ground station located at Malindi, Kenya. The mission's 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.clavin@jpl.nasa.gov


2013-270
Posted by Nelio Inacio at 4:23 PM 0 comments

NASA Evaluates Four Candidate Sites for 2016 Mars Mission

NASA Evaluates Four Candidate Sites for 2016 Mars Mission:

Landing Area Narrowed for 2016 InSight Mission to Mars
The process of selecting a site for NASA's next landing on Mars, planned for September 2016, has narrowed to four semifinalist sites located close together in the Elysium Planitia region of Mars. The mission known by the acronym InSight will study the Red Planet's interior, rather than surface features, to advance understanding of the processes that formed and shaped the rocky planets of the inner solar system, including Earth. Image credit: NASA/JPL-Caltech
› Full image and caption

September 04, 2013

NASA has narrowed to four the number of potential landing sites for the agency's next mission to the surface of Mars, a 2016 lander to study the planet's interior.


The stationary Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport (InSight) lander is scheduled to launch in March 2016 and land on Mars six months later. It will touch down at one of four sites selected in August from a field of 22 candidates. All four semi-finalist spots lie near each other on an equatorial plain in an area of Mars called Elysium Planitia.


"We picked four sites that look safest," said geologist Matt Golombek of NASA's Jet Propulsion Laboratory in Pasadena, Calif. Golombek is leading the site-selection process for InSight. "They have mostly smooth terrain, few rocks and very little slope."


Scientists will focus two of NASA's Mars Reconnaissance Orbiter cameras on the semi-finalists in the coming months to gain data they will use to select the best of the four sites well before InSight is launched.


The mission will investigate processes that formed and shaped Mars and will help scientists better understand the evolution of our inner solar system's rocky planets, including Earth. Unlike previous Mars landings, what is on the surface in the area matters little in the choice of a site except for safety considerations.


"This mission's science goals are not related to any specific location on Mars because we're studying the planet as a whole, down to its core," said Bruce Banerdt, InSight principal investigator at JPL. "Mission safety and survival are what drive our criteria for a landing site."


Each semifinalist site is an ellipse measuring 81 miles (130 kilometers) from east to west and 17 miles (27 kilometers) from north to south. Engineers calculate the spacecraft will have a 99-percent chance of landing within that ellipse, if targeted for the center.


Elysium is one of three areas on Mars that meet two basic engineering constraints for InSight. One requirement is being close enough to the equator for the lander's solar array to have adequate power at all times of the year. Also, the elevation must be low enough to have sufficient atmosphere above the site for a safe landing. The spacecraft will use the atmosphere for deceleration during descent.


All four semifinalist sites, as well as the rest of the 22 candidate sites studied, are in Elysium Planitia. The only other two areas of Mars meeting the requirements of being near the equator at low elevation, Isidis Planitia and Valles Marineris, are too rocky and windy. Valles Marineris also lacks any swath of flat ground large enough for a safe landing.


InSight also needs penetrable ground, so it can deploy a heat-flow probe that will hammer itself 3 yards to 5 yards into the surface to monitor heat coming from the planet's interior. This tool can penetrate through broken-up surface material or soil, but could be foiled by solid bedrock or large rocks.


"For this mission, we needed to look below the surface to evaluate candidate landing sites," Golombek said.


InSight's heat probe must penetrate the ground to the needed depth, so scientists studied Mars Reconnaissance Orbiter images of large rocks near Martian craters formed by asteroid impacts. Impacts excavate rocks from the subsurface, so by looking in the area surrounding craters, the scientists could tell if the subsurface would have probe-blocking rocks lurking beneath the soil surface.


InSight also will deploy a seismometer on the surface and will use its radio for scientific measurements.


JPL manages InSight for NASA's Science Mission Directorate in Washington. The French space agency, Centre National d'Etudes Spatiales, and the German Aerospace Center are contributing instruments to the mission. Lockheed Martin Space Systems, Denver, is building the spacecraft.


InSight is part of NASA's Discovery Program, which NASA's Marshall Space Flight Center in Huntsville, Ala., manages. InSight's team includes U.S. and international co-investigators from universities, industry and government agencies.


For more information about InSight, visit: http://insight.jpl.nasa.gov . Additional information on the Discovery Program is available at: http://discovery.nasa.gov .

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


2013-269
Posted by Nelio Inacio at 4:22 PM 0 comments

Cassini Sees Saturn Storm's Explosive Power

Cassini Sees Saturn Storm's Explosive Power:

Two Looks at the Turbulent Saturn Storm
This set of images from NASA's Cassini mission shows the turbulent power of a monster Saturn storm. The visible-light image in the back, obtained on Feb. 25, 2011, by Cassini's imaging camera, shows the turbulent clouds churning across the face of Saturn. The inset infrared image, obtained a day earlier, by Cassini's visual and infrared mapping spectrometer, shows the dredging up of water and ammonia ices from deep in Saturn's atmosphere. This was the first time water ice was detected in Saturn's atmosphere. The storm, first detected by Cassini's radio and plasma wave subsystem in December 2011, churned around the planet in a band around 33 degrees north. Image Credit:
NASA/JPL-Caltech/SSI/Univ. of Arizona/Univ. of Wisconsin
› Full image and caption
› The visible-light image can be seen separately
› A separate version of the infrared image

September 03, 2013

A monster storm that erupted on Saturn in late 2010 - as large as any storm ever observed on the ringed planet -- has already impressed researchers with its intensity and long-lived turbulence. A new paper in the journal Icarus reveals another facet of the storm's explosive power: its ability to churn up water ice from great depths. This finding, derived from near-infrared measurements by NASA's Cassini spacecraft, is the first detection at Saturn of water ice. The water originates from deep in Saturn's atmosphere.


"The new finding from Cassini shows that Saturn can dredge up material from more than 100 miles [160 kilometers]," said Kevin Baines, a co-author of the paper who works at the University of Wisconsin-Madison and NASA's Jet Propulsion Laboratory, Pasadena, Calif. "It demonstrates in a very real sense that typically demure-looking Saturn can be just as explosive or even more so than typically stormy Jupiter." Water ice, which originates from deep in the atmosphere of gas giants, doesn't appear to be lofted as high at Jupiter.


Monster storms rip across the northern hemisphere of Saturn once every 30 years or so, or roughly once per Saturn year. The first hint of the most recent storm first appeared in data from Cassini's radio and plasma wave subsystem on Dec. 5, 2010. Soon after that, it could be seen in images from amateur astronomers and from Cassini's imaging science subsystem. The storm quickly grew to superstorm proportions, encircling the planet at about 30 degrees north latitude for an expanse of nearly 190,000 miles (300,000 kilometers).


The new paper focuses on data gathered by Cassini's visual and infrared mapping spectrometer on Feb. 24, 2011. The team, led by Lawrence Sromovsky, also of the University of Wisconsin, found that cloud particles at the top of the great storm are composed of a mix of three substances: water ice, ammonia ice, and an uncertain third constituent that is possibly ammonium hydrosulfide. The observations are consistent with clouds of different chemical compositions existing side-by-side, though it is more likely that the individual cloud particles are composed of two or all three of the materials.


The classic model of Saturn's atmosphere portrays it as a layered sandwich of sorts, with a deck of water clouds at the bottom, ammonia hydrosulfide clouds in the middle, and ammonia clouds near the top. Those layers are just below an upper tropospheric haze of unknown composition that obscures almost everything.


But this storm appears to have disrupted those neat layers, lofting up water vapor from a lower layer that condensed and froze as it rose. The water ice crystals then appeared to become coated with more volatile materials like ammonium hydrosulfide and ammonia as the temperature decreased with their ascent, the authors said.


"We think this huge thunderstorm is driving these cloud particles upward, sort of like a volcano bringing up material from the depths and making it visible from outside the atmosphere," said Sromovsky. "The upper haze is so optically thick that it is only in the stormy regions where the haze is penetrated by powerful updrafts that you can see evidence for the ammonia ice and the water ice. Those storm particles have an infrared color signature that is very different from the haze particles in the surrounding atmosphere."


In understanding the dynamics of this Saturn storm, researchers realized that it worked like the much smaller convective storms on Earth, where air and water vapor are pushed high into the atmosphere, resulting in the towering, billowing clouds of a thunderstorm. The towering clouds in Saturn storms of this type, however, were 10 to 20 times taller and covered a much bigger area. They are also far more violent than an Earth storm, with models predicting vertical winds of more than about 300 mph (500 kilometers per hour) for these rare giant storms.


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate, Washington. The California Institute of Technology in Pasadena manages JPL for NASA. The VIMS team is based at the University of Arizona in Tucson.


For more information about the Cassini mission, 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


Terry Devitt 608-262-8282

University of Wisconsin, Madison

trdevitt@wisc.edu

2013-268
Posted by Nelio Inacio at 4:22 PM 0 comments

NASA Voyager Statement About Solar Wind Models

NASA Voyager Statement About Solar Wind Models:

The Space Between: This artist's concept shows the Voyager 1
The Space Between: This artist's concept shows the Voyager 1 spacecraft entering the space between stars. Interstellar space is dominated by plasma, ionized gas (illustrated here as brownish haze), that was thrown off by giant stars millions of years ago. Image credit: NASA/JPL-Caltech
› Full image and caption


July 23, 2014

A paper recently published in the journal Geophysical Research Letters describes an alternate model for the interaction between the heliosphere -- a "bubble" around our planets and sun -- and the interstellar medium. It also proposes a test for whether Voyager 1 has, indeed, left the heliosphere.

NASA's Voyager project scientist, Ed Stone of the California Institute of Technology in Pasadena, responds:

"It is the nature of the scientific process that alternative theories are developed in order to account for new observations. This paper differs from other models of the solar wind and the heliosphere and is among the new models that the Voyager team will be studying as more data are acquired by Voyager."

Stone went on to explain that other models, which he and colleagues used to conclude that Voyager 1 entered interstellar space, predict that the density of interstellar wind outside the heliosphere is 40 times greater than the density of the solar wind inside.

Voyager scientists had carefully analyzed the observational data from the spacecraft, which revealed a plasma density that was 40 times higher. They then concluded that Voyager 1 had departed the solar bubble and entered interstellar space around August 25, 2012.

But the new article argues that solar wind inside the heliosphere can be compressed to the point that the solar wind density inside is just as high as interstellar space outside. Therefore, Voyager 1 could still be inside.

Authors of the new study predict that if Voyager 1 is still inside the heliosphere, the spacecraft will observe a reversal in direction of the solar magnetic field sometime before the end of 2015. Stone said he and colleagues will be looking carefully at the magnetic field data over the coming 18 months to see if Voyager picks up this change.

The Voyager spacecraft were built and continue to be operated by NASA's Jet Propulsion Laboratory, in Pasadena, California. Caltech 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 Voyager, visit:

http://www.nasa.gov/voyager
http://voyager.jpl.nasa.gov

Elizabeth Landau

NASA's Jet Propulsion Laboratory, Pasadena, Calif.

818-354-6425

Elizabeth.Landau@jpl.nasa.gov


2014-238
Posted by Nelio Inacio at 4:20 PM 0 comments

The Most Precise Measurement of an Alien World's Size

The Most Precise Measurement of an Alien World's Size:

Gauging an Alien World's Size
Using data from NASA's Kepler and Spitzer Space Telescopes, scientists have made the most precise measurement ever of the size of a world outside our solar system, as illustrated in this artist's conception.
› Full image and caption


July 23, 2014

Thanks to NASA's Kepler and Spitzer Space Telescopes, scientists have made the most precise measurement ever of the radius of a planet outside our solar system. The size of the exoplanet, dubbed Kepler-93b, is now known to an uncertainty of just 74 miles (119 kilometers) on either side of the planetary body.

The findings confirm Kepler-93b as a "super-Earth" that is about one-and-a-half times the size of our planet. Although super-Earths are common in the galaxy, none exist in our solar system. Exoplanets like Kepler-93b are therefore our only laboratories to study this major class of planet.

With good limits on the sizes and masses of super-Earths, scientists can finally start to theorize about what makes up these weird worlds. Previous measurements, by the Keck Observatory in Hawaii, had put Kepler-93b's mass at about 3.8 times that of Earth. The density of Kepler-93b, derived from its mass and newly obtained radius, indicates the planet is in fact very likely made of iron and rock, like Earth.

"With Kepler and Spitzer, we've captured the most precise measurement to date of an alien planet's size, which is critical for understanding these far-off worlds," said Sarah Ballard, a NASA Carl Sagan Fellow at the University of Washington in Seattle and lead author of a paper on the findings published in the Astrophysical Journal.

"The measurement is so precise that it's literally like being able to measure the height of a six-foot tall person to within three quarters of an inch -- if that person were standing on Jupiter," said Ballard.

Kepler-93b orbits a star located about 300 light-years away, with approximately 90 percent of the sun's mass and radius. The exoplanet's orbital distance -- only about one-sixth that of Mercury's from the sun -- implies a scorching surface temperature around 1,400 degrees Fahrenheit (760 degrees Celsius). Despite its newfound similarities in composition to Earth, Kepler-93b is far too hot for life.

To make the key measurement about this toasty exoplanet's radius, the Kepler and Spitzer telescopes each watched Kepler-93b cross, or transit, the face of its star, eclipsing a tiny portion of starlight. Kepler's unflinching gaze also simultaneously tracked the dimming of the star caused by seismic waves moving within its interior. These readings encode precise information about the star's interior. The team leveraged them to narrowly gauge the star's radius, which is crucial for measuring the planetary radius.

Spitzer, meanwhile, confirmed that the exoplanet's transit looked the same in infrared light as in Kepler's visible-light observations. These corroborating data from Spitzer -- some of which were gathered in a new, precision observing mode -- ruled out the possibility that Kepler's detection of the exoplanet was bogus, or a so-called false positive.

Taken together, the data boast an error bar of just one percent of the radius of Kepler-93b. The measurements mean that the planet, estimated at about 11,700 miles (18,800 kilometers) in diameter, could be bigger or smaller by about 150 miles (240 kilometers), the approximate distance between Washington, D.C., and Philadelphia.

Spitzer racked up a total of seven transits of Kepler-93b between 2010 and 2011. Three of the transits were snapped using a "peak-up" observational technique. In 2011, Spitzer engineers repurposed the spacecraft's peak-up camera, originally used to point the telescope precisely, to control where light lands on individual pixels within Spitzer's infrared camera.

The upshot of this rejiggering: Ballard and her colleagues were able to cut in half the range of uncertainty of the Spitzer measurements of the exoplanet radius, improving the agreement between the Spitzer and Kepler measurements.

"Ballard and her team have made a major scientific advance while demonstrating the power of Spitzer's new approach to exoplanet observations," said Michael Werner, project scientist for the Spitzer Space Telescope at NASA's Jet Propulsion Laboratory, Pasadena, California.

JPL manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.

NASA's Ames Research Center in Moffett Field, California, is responsible for Kepler's ground system development, mission operations and science data analysis. JPL managed Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colorado, developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery Mission and was funded by the agency's Science Mission Directorate.

For more information about the Kepler mission, visit:

http://www.nasa.gov/kepler

For more information about Spitzer, visit:

http://spitzer.caltech.edu

http://www.nasa.gov/spitzer

Whitney Clavin

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-4673

whitney.clavin@jpl.nasa.gov


2014-239
Posted by Nelio Inacio at 4:20 PM 0 comments

NASA Seeks Proposals for Commercial Mars Data Relay Satellites

NASA Seeks Proposals for Commercial Mars Data Relay Satellites:

Artist rendering of commercial Mars satellites providing communications back to Earth.
Artist rendering of commercial Mars satellites providing communications back to Earth.
Image Credit: NASA/JPL-Caltech

› Larger image


July 23, 2014

NASA has issued a Request for Information (RFI) to investigate the possibility of using commercial Mars-orbiting satellites to provide telecommunications capabilities for future robotic missions to the Red Planet.

"We are looking to broaden participation in the exploration of Mars to include new models for government and commercial partnerships," said John Grunsfeld, associate administrator of NASA's Science Mission Directorate at the agency's headquarters in Washington. "Depending on the outcome, the new model could be a vital component in future science missions and the path for humans to Mars."

The RFI details possible new business models that would involve NASA contracting to purchase services from a commercial service provider, which would own and operate one or more communication relay orbiters. The solicitation is open to all types of organizations including U.S. industry, universities, nonprofits, NASA centers, and federally funded research and development centers, in addition to U.S. government and international organizations.

NASA is interested in exploring alternative models to sustain and evolve its Mars' communications relay infrastructure to avoid a communications gap in the 2020s. The RFI encourages innovative ideas for cost-effective approaches that provide relay services for existing landers, as well as significantly improving communications performance.

One possible area for improvement is laser or optical communications. NASA successfully demonstrated laser communications technology in October 2013 with its Lunar Atmosphere and Dust Environment Explorer (LADEE) mission. LADEE made history using a pulsed laser beam to transmit data over 239,000 miles from the moon to Earth at a record-breaking download rate of 622 megabits-per-second (Mbps).

Mars landers and rovers currently transmit their science data and other information to Earth either by a direct communication link or via orbiting satellites acting as relay stations. The direct link is severely limited because of mass, volume, and power limits on the rovers. To address these limits, NASA's Mars Exploration Program currently uses relay radios on its Mars science orbiters. The spacecraft carry high-gain antennas and higher power transmitters that provide very high-rate, energy-efficient links between orbiters and surface missions as the obiters pass overhead.

NASA currently is operating two Mars science orbiters with relay capabilities -- Odyssey, launched in 2001, and the Mars Reconnaissance Orbiter (MRO), launched in 2005. These spacecraft enable communication links from the Curiosity and Opportunity rovers on Mars' surface. This approach will continue with the Sept. 21 arrival of the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft, and the 2016 arrival of the European Space Agency's ExoMars/Trace Gas Orbiter.

"This Mars relay strategy has been extremely successful in providing the science and engineering data returned from the Martian surface over the past decade," said Lisa May, lead program executive for Mars Exploration Program in Washington.

Because NASA has launched science orbiters to Mars on a steady cadence, the current strategy has been cost effective. However, NASA has no scheduled Mars science orbiters after MAVEN arrives on the Red Planet in the fall. This creates the need to identify cost-effective options to ensure continuity of reliable, high-performance telecommunications relay services for the future.

"Looking ahead, we need to seriously explore the possibility of the commercialization of Mars communications services," said May. "This will offer advantages to NASA, while also providing appropriate return-on-investment to the service provider."

The RFI is for planning and information purposes only. It is not to be construed as a commitment by the government to enter into a contractual agreement, nor will the government pay for information solicited.

To view the complete RFI, visit:

http://go.nasa.gov/1kV6KYj

For more information on NASA Mars missions, visit:

http://www.nasa.gov/mars

For information on the LADEE mission, visit:

http://www.nasa.gov/ladee

NASA's Jet Propulsion Laboratory, Pasadena, California, manages the Mars Reconnaissance Orbiter, Mars Odyssey, Opportunity and Curiosity missions. JPL is a division of the California Institute of Technology in Pasadena.

Dwayne Brown

NASA Headquarters, Washington

202-358-1726

dwayne.c.brown@nasa.gov


2014-240
Posted by Nelio Inacio at 4:19 PM 0 comments

NEOWISE Spots a Comet That Looked Like an Asteroid

NEOWISE Spots a Comet That Looked Like an Asteroid:

NEOWISE Spies Activity on Comet Catalina
Comet C/2013 UQ4 (Catalina) appeared to be a highly active comet one day past perihelion on July 7, 2014. Image credit: NASA/JPL-Caltech
› Full image and caption


July 23, 2014

Comet C/2013 UQ4 (Catalina) has been observed by NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) spacecraft just one day after passing through its closest approach to the sun. The comet glows brightly in infrared wavelengths, with a dust tail streaking more than 62,000 miles (100,000 kilometers) across the sky. Its spectacular activity is driven by the vaporization of ice that has been preserved from the time of planet formation 4.5 billion years ago.

"The tail forms a faint fan as the smaller dust particles are more easily pushed away from the sun by the radiation pressure of the sunlight," said James Bauer, researcher at NASA's Jet Propulsion Laboratory in Pasadena, California.

C/2013 UQ4 takes more than 450 years to orbit the sun once and spends most of its time far away at very low temperatures. Its orbit is also retrograde, which means that the comet moves around the sun in the opposite direction to the planets and asteroids.

The comet was originally thought to be an asteroid, as it appeared inactive when discovered by the Catalina Sky Survey on October 23, 2013. NEOWISE also observed the comet to be inactive on New Year's Eve, 2013, but since then the comet has become highly active, allowing astronomers around the world to observe it. The comet's activity should decline as it once again returns to the cold recesses of space.

NASA's Jet Propulsion Laboratory manages the NEOWISE mission for NASA's Science Mission Directorate in Washington. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colo., built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. For more information about NEOWISE, visit:

http://www.nasa.gov/neowise

Elizabeth Landau

818-354-6425

Jet Propulsion Laboratory, Pasadena, Calif.

elizabeth.landau@jpl.nasa.gov


2014-241
Posted by Nelio Inacio at 4:19 PM 0 comments

Tuesday, July 22, 2014

Comet Found Hiding in Plain Sight

Comet Found Hiding in Plain Sight:

Spitzer Spies a Comet Coma and Tail
With the help of NASA's Spitzer Space Telescope, astronomers have discovered that what was thought to be a large asteroid called Don Quixote is in fact a comet. Image credit: NASA/JPL-Caltech/DLR/NAU
› Full image and caption

September 10, 2013

For 30 years, a large near-Earth asteroid wandered its lone, intrepid path, passing before the scrutinizing eyes of scientists armed with telescopes while keeping something to itself. The object, known as Don Quixote, whose journey stretches to the orbit of Jupiter, now appears to be a comet.


The discovery resulted from an ongoing project coordinated by researchers at Northern Arizona University, Flagstaff, Ariz., using NASA's Spitzer Space Telescope. Through a lot of focused attention and a little luck, they found evidence of comet activity, which had evaded detection for three decades.


The results show that Don Quixote is not, in fact, a dead comet, as previously believed, but it has a faint coma and tail. In fact, this object, the third-biggest near-Earth asteroid known, skirts Earth with an erratic, extended orbit and is "sopping wet," said David Trilling of Northern Arizona University, with large deposits of carbon dioxide and presumably water ice. Don Quixote is about 11 miles (18 kilometers) long.


"This discovery of carbon dioxide emission from Don Quixote required the sensitivity and infrared wavelengths of the Spitzer telescope and would not have been possible using telescopes on the ground," said Michael Mommert, who conducted the research at the German Aerospace Center, Berlin, before moving to Northern Arizona University. This discovery implies that carbon dioxide and water ice might be present on other near-Earth asteroids, as well.


The implications have less to do with a potential impact, which is extremely unlikely in this case, and more with "the origins of water on Earth," Trilling said. Impacts with comets like Don Quixote over geological time may be the source of at least some of it, and the amount on Don Quixote represents about 100 billion tons of water -- roughly the same amount that can be found in Lake Tahoe, Calif.


Mommert presented the results at the European Planetary Science Congress in London on Sept. 10.


Read the full news release from Northern Arizona University at http://news.nau.edu/nau-led-teams-discovers-comet-hiding-in-plain-sight/ .


NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA. For more information about Spitzer, visit http://spitzer.caltech.edu and http://www.nasa.gov/spitzer .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-274
Posted by Nelio Inacio at 6:43 PM 0 comments
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'La Nada' Climate Pattern Lingers in the Pacific

'La Nada' Climate Pattern Lingers in the Pacific:

The latest image of sea surface heights in the Pacific Ocean from NASA's Jason-2 satellite
The latest image of sea surface heights in the Pacific Ocean from NASA's Jason-2 satellite shows that the equatorial Pacific Ocean is now in its 16th month of being locked in what some call a neutral, or "La Nada" state.
Image credit: NASA-JPL/Caltech/Ocean Surface Topography Team

› Full image and caption

September 09, 2013

UPDATE - SEPT. 10: After publication of this image on Sept. 9, a small error was discovered in the original processing of the data that were used to generate the Aug. 27, 2013 Jason-2 image. The image has been updated accordingly. The data used to generate the reprocessed image are the same, and the discussion and analysis of the data in the news story below remains unchanged.


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New remote sensing data from NASA's Jason-2 satellite show near-normal sea-surface height conditions across the equatorial Pacific Ocean. This neutral, or "La Nada" event, has stubbornly persisted for 16 months, since spring 2012. Models suggest this pattern will continue through the spring of 2014, according to the National Weather Service's Climate Prediction Center.


"Without an El Niño or La Niña signal present, other, less predictable, climatic factors will govern fall, winter and spring weather conditions," said climatologist Bill Patzert of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Long-range forecasts are most successful during El Niño and La Niña episodes. The 'in between' ocean state, La Nada, is the dominant condition, and is frustrating for long-range forecasters. It's like driving without a decent road map -- it makes forecasting difficult."


The near-normal conditions are shown in a new image (as areas shaded in green), based on the average of 10 days of data centered on Aug. 27, 2013. The image is available at: http://www.jpl.nasa.gov/spaceimages/details.php?id=pia17454 .


For the past several decades, about half of all years have experienced La Nada conditions, compared to about 20 percent for El Niño and 30 percent for La Niña.


Patzert noted that some of the wettest and driest winters occur during La Nada periods.


"Neutral infers something benign, but in fact if you look at these La Nada years when neither El Niño nor La Niña are present, they can be the most volatile and punishing. As an example, the continuing, deepening drought in the American West is far from 'neutral,'" he said.


The height of the sea water relates, in part, to its temperature, and thus is an indicator of the amount of heat stored in the ocean below. As the ocean warms, its level rises; as it cools, its level falls. Yellow and red areas indicate where the waters are relatively warmer and have expanded above normal sea level, while green (which dominates in this image) indicates near-normal sea level, and blue and purple areas show where the waters are relatively colder and sea level is lower than normal. Above-normal height variations along the equatorial Pacific indicate El Niño conditions, while below-normal height variations indicate La Niña conditions. The temperature of the upper ocean can have a significant influence on weather patterns and climate. For a more detailed explanation of what this type of image means, visit: http://sealevel.jpl.nasa.gov/science/elninopdo/latestdata/.


This latest image highlights the processes that occur on time scales of more than a year, but usually less than 10 years, such as El Niño and La Niña. These processes are known as the interannual ocean signal. To show that signal, scientists refined data for this image by removing trends over the past 20 years, seasonal variations and time-averaged signals of large-scale ocean circulation.


NASA scientists will continue to monitor this persistent La Nada event to see what the Pacific Ocean has in store next for the world's climate.


The comings and goings of El Niño, La Niña and La Nada are part of the long-term, evolving state of global climate, for which measurements of sea surface height are a key indicator. Jason-2 is a joint effort between NASA, the National Oceanic and Atmospheric Administration (NOAA), the French Space Agency Centre National d'Etudes Spatiales (CNES) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). JPL manages the U.S. portion of Jason-2 for NASA's Science Mission Directorate, Washington, D.C.
In early 2015, NASA and its international partners CNES, NOAA and EUMETSAT will launch Jason-3, which will extend the timeline of ocean surface topography measurements begun by the Topex/Poseidon and Jason 1 and 2 satellites. Jason-3 will make highly detailed measurements of sea level on Earth to gain insight into ocean circulation and climate change.


For more on NASA's satellite altimetry programs, visit: http://sealevel.jpl.nasa.gov.

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

alan.buis@jpl.nasa.gov


2013-272
Posted by Nelio Inacio at 6:43 PM 0 comments
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