Wednesday, July 30, 2014

Kepler Data Suggest Earth-size Planets May Be Next Door

Kepler Data Suggest Earth-size Planets May Be Next Door:

Astronomers estimate that six percent of red dwarfs have a temperate Earth-size planet, as close as 13 light-years away.
Astronomers estimate that six percent of red dwarfs have a temperate Earth-size planet, as close as 13 light-years away. Image credit: D. Aguilar/Harvard-Smithsonian Center for Astrophysics

› Full image and caption

February 06, 2013

Using publicly available data from NASA's Kepler space telescope, astronomers at the Harvard-Smithsonian Center for Astrophysics estimate that six percent of red dwarf stars in the galaxy have Earth-size planets in the "habitable zone," the range of distances from a star where the surface temperature of an orbiting planet might be suitable for liquid water.


The majority of the sun's closest stellar neighbors are red dwarfs. Researchers now believe that an Earth-size planet with a moderate temperature may be just 13 light-years away.


"We don't know if life could exist on a planet orbiting a red dwarf, but the findings pique my curiosity and leave me wondering if the cosmic cradles of life are more diverse than we humans have imagined," said Natalie Batalha, Kepler mission scientist at NASA's Ames Research Center in Moffett Field, Calif.


The research team analyzed 95 planet candidates in the Kepler catalog orbiting 64 red dwarf stars. Most of these candidates aren't the right size or temperature to be considered Earth-like, as defined by the size relative to Earth and the distance from the host star. However, three candidates are both temperate and smaller than twice the size of Earth.


Red dwarf stars are smaller, cooler and fainter than our sun. An average red dwarf is only one-third as large and one-thousandth as bright as the sun. Consequently, the not-too-hot or not-too-cold habitable zone would be much closer to a cooler star than it is to the sun.


"This close-in habitable zone around cooler stars makes planets more vulnerable to the effects of stellar flares and gravitational interactions, complicating our understanding of their likely habitability," said Victoria Meadows, professor at the University of Washington, Seattle, and principal investigator with the NASA Astrobiology Institute. "But, if the planets predicted by this study are indeed found very nearby, then it will make it easier for us to make the challenging observations needed to learn more about them, including whether or not they can or do support life."


The three planetary candidates highlighted in this study are Kepler Object of Interest (KOI) 1422.02, which is 90 percent the size of Earth in a 20-day orbit; KOI-2626.01, 1.4 times the size of Earth in a 38-day orbit; and KOI-854.01, 1.7 times the size of Earth in a 56-day orbit.


Located between 300 and 600 light-years away, the three candidates orbit stars with temperatures ranging from 5,660 to 5,840 degrees Fahrenheit (3,400 to 3,500 degrees Kelvin). By comparison, the temperature of the sun is nearly 5,800 degrees Kelvin (9,980 degrees Fahrenheit).


Kepler is the first NASA mission capable of finding Earth-size planets in or near the habitable zone. Kepler is detecting planets and possible candidates with a wide range of sizes and orbital distances to help scientists better understand our place in the galaxy.


Ames manages Kepler's ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development. Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with JPL at 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 the Kepler science data. Kepler is NASA's 10th Discovery Mission and is funded by NASA's Science Mission Directorate at the agency's headquarters.


For more information about the discovery, see the full press release .


For information about the Kepler Mission, visit: http://www.nasa.gov/kepler .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-048
Posted by Nelio Inacio at 5:57 AM 0 comments

NASA Telescopes Discover Strobe-Like Flashes in Young Stars

NASA Telescopes Discover Strobe-Like Flashes in Young Stars:

Artist's Impression of Pulsating Object LRLL 54361
This is an artist's impression of two young binary stars that may be the source of mysterious clock-like bursts of light from an object called LRLL 54361 that lies inside the star-forming region IC 348, located 950 light-years away. Image credit: NASA/ESA/JPL-Caltech
› Full image and caption

February 07, 2013

PASADENA, Calif.-- Two of NASA's great observatories, the Spitzer and Hubble space telescopes, have teamed up to uncover a mysterious infant star that behaves like a strobe light.


Every 25.34 days, the object, designated LRLL 54361, unleashes a burst of light. Although a similar phenomenon has been observed in two other young stellar objects, this is the most powerful such beacon seen to date.


The heart of the fireworks is hidden behind a dense disk and an envelope of dust. Astronomers propose the light flashes are caused by periodic interactions between two newly formed stars that are binary, or gravitationally bound to each other. LRLL 54361 offers insights into the early stages of star formation when lots of gas and dust is being rapidly accreted, or pulled together, to form a new binary star.


Astronomers theorize the flashes are caused by material suddenly being dumped onto the growing stars, known as protostars. A blast of radiation is unleashed each time the stars get close to each other in their orbits. This phenomenon, called pulsed accretion, has been seen in later stages of star birth, but never in such a young system or with such intensity and regularity.


"This protostar has such large brightness variations with a precise period that it is very difficult to explain," said James Muzerolle of the Space Telescope Science Institute in Baltimore, Md. His paper recently was published in the science journal Nature.


Discovered by NASA's Spitzer Space Telescope, LRLL 54361 is a variable object inside the star-forming region IC 348, located 950 light-years from Earth. Data from Spitzer revealed the presence of protostars. Based on statistical analysis, the two stars are estimated to be no more than a few hundred thousand years old.


The Spitzer infrared data, collected repeatedly during a period of seven years, showed unusual outbursts in the brightness of the suspected binary protostar. Surprisingly, the outbursts recurred every 25.34 days, which is a very rare phenomenon.


Astronomers used NASA's Hubble Space Telescope to confirm the Spitzer observations and reveal the detailed stellar structure around LRLL 54361. Hubble observed two cavities above and below a dusty disk. The cavities are visible by tracing light scattered off their edges. They likely were blown out of the surrounding natal envelope of dust and gas by an outflow launched near the central stars. The disk and the envelope prevent the suspected binary star pair from being observed directly. By capturing multiple images over the course of one pulse event, the Hubble observations uncovered a spectacular movement of light away from the center of the system, an optical illusion known as a light echo.


Muzerolle and his team hypothesized the pair of stars in the center of the dust cloud move around one another in a very eccentric orbit. As the stars approach each other, dust and gas are dragged from the inner edge of a surrounding disk. The material ultimately crashes onto one or both stars, which triggers a flash of light that illuminates the circumstellar dust. The system is rare because close binaries account for only a few percent of our galaxy's stellar population. This is likely a brief, transitory phase in the birth of a star system.


Muzerolle's team next plans to continue monitoring LRLL 54361 using other facilities, including the European Space Agency's Herschel Space Telescope. The team hopes to eventually obtain more direct measurements of the binary star and its orbit.


For related images and video, visit: http://hubblesite.org/news/2013/04 .


NASA's Jet Propulsion Laboratory, Pasadena, Calif., 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. 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 .


The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md.,
manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc., in Washington. For more information on Hubble visit: www.nasa.gov/hubble and http://hubblesite.org/ .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


Ray Villard 410-338-4514

Space Telescope Science Institute, Baltimore, Md.

villard@stsci.edu


J.D. Harrington 202-358-5241

Headquarters, Washington

j.d.harrington@nasa.gov


2013-050
Posted by Nelio Inacio at 5:56 AM 0 comments

NASA Satellites Find Freshwater Losses in Middle East

NASA Satellites Find Freshwater Losses in Middle East:

Variations in total water storage from normal, in millimeters, in the Tigris and Euphrates river basins
Variations in total water storage from normal, in millimeters, in the Tigris and Euphrates river basins, as measured by NASA's Gravity Recovery and Climate Experiment (GRACE) satellites, from January 2003 through December 2009. Reds represent drier conditions, while blues represent wetter conditions. The majority of the water lost was due to reductions in groundwater caused by human activities. By periodically measuring gravity regionally, GRACE tells scientists how much water storage changes over time. Image credit: NASA/UC Irvine/NCAR
› Larger image

February 12, 2013

PASADENA, Calif. - A new study using data from a pair of gravity-measuring NASA satellites finds that large parts of the arid Middle East region lost freshwater reserves rapidly during the past decade.


Scientists at the University of California, Irvine; NASA's Goddard Space Flight Center in Greenbelt, Md.; and the National Center for Atmospheric Research in Boulder, Colo., found during a seven-year period beginning in 2003 that parts of Turkey, Syria, Iraq and Iran along the Tigris and Euphrates river basins lost 117 million acre feet (144 cubic kilometers) of total stored freshwater. That is almost the amount of water in the Dead Sea. The researchers attribute about 60 percent of the loss to pumping of groundwater from underground reservoirs.


The findings, to be published Friday, Feb. 15, in the journal Water Resources Research, are the result of one of the first comprehensive hydrological assessments of the entire Tigris-Euphrates-Western Iran region. Because obtaining ground-based data in the area is difficult, satellite data, such as those from NASA's twin Gravity Recovery and Climate Experiment (GRACE) satellites, are essential. GRACE is providing a global picture of water storage trends and is invaluable when hydrologic observations are not routinely collected or shared beyond political boundaries.


"GRACE data show an alarming rate of decrease in total water storage in the Tigris and Euphrates river basins, which currently have the second fastest rate of groundwater storage loss on Earth, after India," said Jay Famiglietti, principal investigator of the study and a hydrologist and professor at UC Irvine. "The rate was especially striking after the 2007 drought. Meanwhile, demand for freshwater continues to rise, and the region does not coordinate its water management because of different interpretations of international laws."


Famiglietti said GRACE is like having a giant scale in the sky. Within a given region, rising or falling water reserves alter Earth's mass, influencing how strong the local gravitational attraction is. By periodically measuring gravity regionally, GRACE tells us how much each region's water storage changes over time.


"GRACE really is the only way we can estimate groundwater storage changes from space right now," Famiglietti said.


The team calculated about one-fifth of the observed water losses resulted from soil drying up and snowpack shrinking, partly in response to the 2007 drought. Loss of surface water from lakes and reservoirs accounted for about another fifth of the losses. The majority of the water lost -- approximately 73 million acre feet (90 cubic kilometers) -- was due to reductions in groundwater.


"That's enough water to meet the needs of tens of millions to more than a hundred million people in the region each year, depending on regional water use standards and availability," said Famiglietti.


Famiglietti said when a drought reduces an available surface water supply, irrigators and other water users turn to groundwater supplies. For example, the Iraqi government drilled about 1,000 wells in response to the 2007 drought, a number that does not include the numerous private wells landowners also very likely drilled.


"Water management is a complex issue in the Middle East -- an area that already is dealing with limited water resources and competing stakeholders," said Kate Voss, lead author of the study and a water policy fellow with the University of California's Center for Hydrological Modeling in Irvine, which Famiglietti directs.


"The Middle East just does not have that much water to begin with, and it's a part of the world that will be experiencing less rainfall with climate change," said Famiglietti. "Those dry areas are getting dryer. The Middle East and the world's other arid regions need to manage available water resources as best they can."


Study co-author Matt Rodell of Goddard added it is important to remember groundwater is being extracted unsustainably in parts of the United States, as well.


"Groundwater is like your savings account," Rodell said. "It's okay to draw it down when you need it, but if it's not replenished, eventually it will be gone."


GRACE is a joint mission with the German Aerospace Center and the German Research Center for Geosciences, in partnership with the University of Texas at Austin. For more about GRACE, visit: http://www.nasa.gov/grace and http://www.csr.utexas.edu/grace . 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


Janet Wilson 949-824-3969

University of California, Irvine

janethw@uci.edu


2013-054
Posted by Nelio Inacio at 5:55 AM 0 comments

JPL to Lead U.S. Science Team for Dark Energy Mission

JPL to Lead U.S. Science Team for Dark Energy Mission:

This artist's concept shows the Euclid spacecraft.
This artist's concept shows the Euclid spacecraft. The telescope will launch to an orbit around the sun-Earth Lagrange point L2. The Lagrange point is a location where the gravitational pull of two large masses, the sun and Earth in this case, precisely equals the force required for a small object, such as the Euclid spacecraft, to maintain a relatively stationary position behind Earth as seen from the sun. Image credit: ESA/C. Carreau
› Full image and caption

February 12, 2013

PASADENA, Calif. -- The European Space Agency (ESA) has selected three NASA-nominated science teams to participate in their planned Euclid mission, including one team led by NASA's Jet Propulsion Laboratory in Pasadena, Calif.


NASA is a partner in the Euclid mission, a space telescope designed to probe the mysteries of dark energy and dark matter. Euclid is currently scheduled to launch in 2020.


JPL will provide 16 advanced infrared detectors and four spare detectors for one of two instruments planned for the mission. In addition, JPL will contribute to science planning and data analysis with the help of its 43-member science team, the largest of the three U.S. teams. This team, led by JPL scientist Jason Rhodes, is composed of 29 scientists recently nominated by NASA, and 14 U.S. scientists who are already part of Euclid.


The other two U.S. science teams are led by Ranga-Ram Chary of the Infrared Processing and Analysis Center at the California Institute of Technology, Pasadena; and Alexander Kashlinsky of NASA's Goddard Space Flight Center, Greenbelt, Md.; with three and seven members, respectively.


Rhodes also was appointed by NASA to be a member of ESA's principal 12-member Euclid Science Team and the U.S. representative for the Euclid Consortium's governing body. The Euclid Consortium is an international body of 1,000 members, including the U.S. science team members, and will build the instruments and analyze the science data jointly.


"Understanding the hidden contents of the universe and the nature of the dark energy will require the collaboration of astronomers and engineers around the world," said Rhodes.


Euclid will observe up to two billion galaxies occupying more than one-third of the sky with the goal of better understanding the contents of our universe. Everyday matter that we see around us, for example in tables and chairs, people and even stars, makes up only a few percent of everything in our cosmos. If you could fill a bucket with the mass and energy contents of our universe, this everyday matter would fill only a small fraction. A larger amount, about 24 percent, would consist of dark matter, an invisible substance that does not reflect or emit any light, but exerts a gravitational tug on other matter.


The majority of our universal bucket, about 73 percent, is thought to be filled with dark energy, something even more mysterious than dark matter. Whereas dark matter pulls through its gravity, dark energy is thought to be a repulsive force pushing matter apart. Scientists think dark energy may be responsible for stretching our universe apart at ever-increasing speeds, an observation that earned the Nobel Prize in 2011.


Euclid scientists will use two methods to make the most precise measurements yet of our "dark" universe. The first method, called weak lensing, involves analyzing the shapes of billions of galaxies across more than half the age of the universe. When dark matter lies in front of galaxies, it can't be seen, but its gravity distorts the light from the galaxies behind it. More dark matter will lead to slightly larger distortions. By measuring these minute distortions, scientists can understand the amount and distribution of the dark matter between these galaxies and us.


Changes in these dark matter structures over time are governed by interplay between the attractive force of gravity and the repulsive dark energy. Thus, studying galaxy shapes reveals information about both dark matter and dark energy.


The second method, called galaxy clustering or baryon acoustic oscillations, will serve as an independent measurement of dark energy. Early in the universe, galaxies were imprinted with a standard distance between them. This distance -- referred to as a standard ruler -- expands as the universe itself expands. By making precise measurements of the distances between tens of millions of galaxies, the scientists will be able to chart this expansion and learn more about the dark energy driving it. Observations of how the galaxies are clustered will also further probe dark matter.


The JPL-led U.S. science team will employ both of these methods and work together with the rest of the Euclid scientists to shine light on the darkest riddles of our cosmos. Of the 43 team members, six are based at JPL. They are: Olivier Dore, Peter Eisenhardt, Alina Kiessling, Leonidas Moustakas, Jason Rhodes and Daniel Stern. Two additional team members, Peter Capak and Harry Teplitz, are based at the Infrared Processing and Analysis Center.


Mike Seiffert is the U.S. project scientist for Euclid at JPL, and Ulf Israelsson is the U.S. project manager at JPL.


Euclid is a European Space Agency mission with science instruments and data analysis provided by the Euclid consortium with important participation from NASA. NASA's Euclid Project Office is based at JPL. JPL will contribute the infrared flight detectors for one of Euclid's two science instruments. NASA Goddard will assist with infrared detector characterization and will perform detailed testing on flight detectors prior to delivery. Three U.S. science teams, led by JPL, Goddard and the Infrared Processing and Analysis Center at Caltech, will contribute to science planning and data analysis. Caltech manages JPL for NASA.


More information is online at http://www.nasa.gov/euclid and http://sci.esa.int/euclid .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


J.D. Harrington 202-358-5241

NASA Headquarters, Washington

j.d.harrington@nasa.gov


2013-055
Posted by Nelio Inacio at 5:54 AM 0 comments

NASA to Chronicle Close Earth Flyby of Asteroid

NASA to Chronicle Close Earth Flyby of Asteroid:

Diagram depicting the passage of asteroid 2012 DA14 through the Earth-moon system on Feb. 15, 2013.
Diagram depicting the passage of asteroid 2012 DA14 through the Earth-moon system on Feb. 15, 2013. Image credit: NASA/JPL-Caltech
› Larger image

February 13, 2013

PASADENA, Calif. -- NASA Television will provide commentary starting at 11 a.m. PST (2 p.m. EST) on Friday, Feb. 15, during the close, but safe, flyby of a small near-Earth asteroid named 2012 DA14. NASA places a high priority on tracking asteroids and protecting our home planet from them. This flyby will provide a unique opportunity for researchers to study a near-Earth object up close.


The half-hour broadcast from NASA's Jet Propulsion Laboratory in Pasadena, Calif., will incorporate real-time animation to show the location of the asteroid in relation to Earth, along with live or near real-time views of the asteroid from observatories in Australia, weather permitting.


At the time of its closest approach to Earth at approximately 11:25 a.m. PST (2:25 p.m. EST / 19:25 UTC), the asteroid will be about 17,150 miles (27,600 kilometers) above Earth's surface.


The commentary will be available via NASA TV and streamed live online at:


http://www.nasa.gov/ntv


and


http://www.ustream.tv/nasajpl2


In addition to the commentary, near real-time imagery of the asteroid's flyby before and after closest approach, made available to NASA by astronomers in Australia and Europe, weather permitting, will be streamed beginning at about 9 a.m. PST (noon EST) and continuing through the afternoon at the following website:


http://www.ustream.tv/nasajpl2


A Ustream feed of the flyby from a telescope at NASA's Marshall Space Flight Center in Huntsville, Ala., will be streamed for three hours starting at 6 p.m. PST (8 p.m. CST / 9 p.m. EST). To view the feed and ask researchers questions about the flyby via Twitter, visit:


http://www.ustream.tv/channel/nasa-msfc


The NASA Near Earth Objects (NEO) Program at the agency's headquarters in Washington manages and funds the search, study and monitoring of NEOs, or asteroids and comets, whose orbits periodically bring them close to the Earth. NASA's study of NEOs provides important clues to understanding the origin of our solar system. The objects also are a repository of natural resources and could become waystations for future exploration. In collaboration with other external organizations, one of the program's key goals is to search and hopefully mitigate potential NEO impacts on Earth. JPL conducts the NEO program's technical and scientific activities.


For more information, including graphics and animations showing the flyby of 2012 DA14, visit:


www.nasa.gov/asteroidflyby


For more information about asteroids and near-Earth objects, visit:


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

D.C. Agle 818-393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov


Steve Cole 202-358-0918

NASA Headquarters, Washington

stephen.e.cole@nasa.gov


2013-059
Posted by Nelio Inacio at 5:54 AM 0 comments

Additional Details on the Large Feb. 15 Fireball over Russia

Additional Details on the Large Feb. 15 Fireball over Russia:

A meteor seen flying over Russia on Feb. 15 at 3:20: 26 UTC impacted Chelyabinsk.
A meteor seen flying over Russia on Feb. 15 at 3:20: 26 UTC impacted Chelyabinsk. Preliminary information is that this object was unrelated to asteroid 2012 DA14, which made a safe pass by Earth today. Image credit: Google Earth, NASA/JPL-Caltech

› Larger image

February 15, 2013

Preliminary information indicates that a meteor in Chelyabinsk, Russia, is not related to asteroid 2012 DA14, which is flying by Earth safely today.


The Russia meteor is the largest reported since 1908, when a meteor hit Tunguska, Siberia. The meteor entered the atmosphere at about 40,000 mph (18 kilometers per second). The impact time was 7:20:26 p.m. PST, or 10:20:26 p.m. EST on Feb. 14 (3:20:26 UTC on Feb. 15), and the energy released by the impact was in the hundreds of kilotons.


Based on the duration of the event, it was a very shallow entry. It was larger than the meteor over Indonesia on Oct. 8, 2009. Measurements are still coming in, and a more precise measure of the energy may be available later. The size of the object before hitting the atmosphere was about 49 feet (15 meters) and had a mass of about 7,000 tons.


The meteor, which was about one-third the diameter of asteroid 2012 DA14, was brighter than the sun. Its trail was visible for about 30 seconds, so it was a grazing impact through the atmosphere.


It is important to note that this estimate is preliminary, and may be revised as more data is obtained.

http://www.nasa.gov/topics/solarsystem/features/asteroidflyby.html
Posted by Nelio Inacio at 5:53 AM 0 comments

NASA Releases Radar Movie of Asteroid 2012 DA14

NASA Releases Radar Movie of Asteroid 2012 DA14:

Radar image of asteroid 2012 DA14
This collage of 72 individual radar-generated images of asteroid 2012
DA14 was created using data from NASA's 230-foot (70-meter) Deep Space
Network antenna at Goldstone, Calif.
Image credit: NASA/JPL-Caltech

› Full image and caption

February 19, 2013

An initial sequence of radar images of asteroid 2012 DA14 was obtained on the night of Feb. 15/16, 2013, by NASA scientists using the 230-foot (70-meter) Deep Space Network antenna at Goldstone, Calif. Each of the 72 frames required 320 seconds of data collection by the Goldstone radar.


The observations were made as the asteroid was moving away from Earth. The asteroid's distance from the radar dish increased from 74,000 miles (120,000 kilometers) to 195,000 miles (314,000 kilometers). The resolution is 13 feet (four meters) per pixel. The images span close to eight hours and clearly show an elongated object undergoing roughly one full rotation. The images suggest that the asteroid has a long axis of about 130 feet (40 meters). The radar observations were led by scientists Lance Benner and Marina Brozovic of NASA's Jet Propulsion Laboratory, Pasadena, Calif. Additional Goldstone radar observations are scheduled on February 18, 19 and 20.


Radar is a powerful technique for studying an asteroid's size, shape, rotation state, surface features and surface roughness, and for improving calculations of its orbit. Radar measurements of asteroid distances and velocities often enable computation of asteroid orbits much further into the future than if radar observations weren't available.


NASA detects, tracks and characterizes asteroids and comets passing close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them, and plots their orbits to determine if any could be potentially hazardous to our planet.


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 at: http://www.jpl.nasa.gov/asteroidwatch . More information about asteroid radar research is at: http://echo.jpl.nasa.gov/ . More information about the Deep Space Network is at: http://deepspace.jpl.nasa.gov/dsn .

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


2013-063
Posted by Nelio Inacio at 5:52 AM 0 comments

Cassini Sheds Light on Cosmic Particle Accelerators

Cassini Sheds Light on Cosmic Particle Accelerators:

Cassini at Saturn's bow shock
This artist's impression by the European Space Agency shows NASA's Cassini spacecraft exploring the magnetic environment of Saturn. Image credit: ESA
› Full image and caption

February 19, 2013

During a chance encounter with what appears to be an unusually strong blast of solar wind at Saturn, NASA's Cassini spacecraft detected particles being accelerated to ultra-high energies. This is similar to the acceleration that takes place around distant supernovas.


Since we can't travel out to the far-off stellar explosions right now, the shockwave that forms from the flow of solar wind around Saturn's magnetic field provides a rare laboratory for scientists with the Cassini mission -- a partnership involving NASA, the European Space Agency and the Italian Space Agency -- to observe this phenomenon up-close. The findings, published this week in the journal Nature Physics, confirm that certain kinds of shocks can become considerably more effective electron accelerators than previously thought.


Shock waves are commonplace in the universe, for example in the aftermath of a stellar explosion as debris accelerate outward in a supernova remnant, or when the flow of particles from the sun - the solar wind - impinges on the magnetic field of a planet to form a bow shock. Under certain magnetic field orientations and depending on the strength of the shock, particles can be accelerated to close to the speed of light at these boundaries. These may be the dominant source of cosmic rays, high-energy particles that pervade our galaxy.


Scientists are particularly interested in "quasi-parallel" shocks, where the magnetic field and the "forward"-facing direction of the shock are almost aligned, as may be found in supernova remnants. The new study, led by Adam Masters of the Institute of Space and Astronautical Science, Sagamihara, Japan, describes the first detection of significant acceleration of electrons in a quasi-parallel shock at Saturn, coinciding with what may be the strongest shock ever encountered at the ringed planet.


"Cassini has essentially given us the capability of studying the nature of a supernova shock in situ in our own solar system, bridging the gap to distant high-energy astrophysical phenomena that are usually only studied remotely," said Masters.


The Cassini-Huygens mission is a cooperative project of NASA, ESA and ASI, the Italian space agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington.

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Markus Bauer 011-31-71-565-6799

European Space Agency, Noordwijk, the Netherlands

markus.bauer@esa.int


2013-064
Posted by Nelio Inacio at 5:52 AM 0 comments

NASA's Kepler Mission Discovers Tiny Planet System

NASA's Kepler Mission Discovers Tiny Planet System:

NASA's Kepler mission has discovered a new planetary system
NASA's Kepler mission has discovered a new planetary system that is home to the smallest planet yet found around a star like our sun, approximately 210 light-years away in the constellation Lyra. Credit: NASA/Ames/JPL-Caltech
› Full image and caption

February 20, 2013

PASADENA, Calif. -- NASA's Kepler mission scientists have discovered a new planetary system that is home to the smallest planet yet found around a star similar to our sun.


The planets are located in a system called Kepler-37, about 210 light-years from Earth in the constellation Lyra. The smallest planet, Kepler-37b, is slightly larger than our moon, measuring about one-third the size of Earth. It is smaller than Mercury, which made its detection a challenge.


The moon-size planet and its two companion planets were found by scientists with NASA's Kepler mission, which is designed to find Earth-sized planets in or near the "habitable zone," the region in a planetary system where liquid water might exist on the surface of an orbiting planet. However, while the star in Kepler-37 may be similar to our sun, the system appears quite unlike the solar system in which we live.


Astronomers think Kepler-37b does not have an atmosphere and cannot support life as we know it. The tiny planet almost certainly is rocky in composition. Kepler-37c, the closer neighboring planet, is slightly smaller than Venus, measuring almost three-quarters the size of Earth. Kepler-37d, the farther planet, is twice the size of Earth.


The first exoplanets found to orbit a normal star were giants. As technologies have advanced, smaller and smaller planets have been found, and Kepler has shown that even Earth-size exoplanets are common.


"Even Kepler can only detect such a tiny world around the brightest stars it observes," said Jack Lissauer, a planetary scientist at NASA's Ames Research Center in Moffett Field, Calif. "The fact we've discovered tiny Kepler-37b suggests such little planets are common, and more planetary wonders await as we continue to gather and analyze additional data."


Kepler-37's host star belongs to the same class as our sun, although it is slightly cooler and smaller. All three planets orbit the star at less than the distance Mercury is to the sun, suggesting they are very hot, inhospitable worlds. Kepler-37b orbits every 13 days at less than one-third Mercury's distance from the sun. The estimated surface temperature of this smoldering planet, at more than 800 degrees Fahrenheit (700 degrees Kelvin), would be hot enough to melt the zinc in a penny. Kepler-37c and Kepler-37d, orbit every 21 days and 40 days, respectively.


"We uncovered a planet smaller than any in our solar system orbiting one of the few stars that is both bright and quiet, where signal detection was possible," said Thomas Barclay, Kepler scientist at the Bay Area Environmental Research Institute in Sonoma, Calif., and lead author of the new study published in the journal Nature. "This discovery shows close-in planets can be smaller, as well as much larger, than planets orbiting our sun."


The research team used data from NASA's Kepler space telescope, which simultaneously and continuously measures the brightness of more than 150,000 stars every 30 minutes. When a planet candidate transits, or passes, in front of the star from the spacecraft's vantage point, a percentage of light from the star is blocked. This causes a dip in the brightness of the starlight that reveals the transiting planet's size relative to its star.


The size of the star must be known in order to measure the planet's size accurately. To learn more about the properties of the star Kepler-37, scientists examined sound waves generated by the boiling motion beneath the surface of the star. They probed the interior structure of Kepler-37's star just as geologists use seismic waves generated by earthquakes to probe the interior structure of Earth. The science is called asteroseismology.


The sound waves travel into the star and bring information back up to the surface. The waves cause oscillations that Kepler observes as a rapid flickering of the star's brightness. Like bells in a steeple, small stars ring at high tones while larger stars boom in lower tones. The barely discernible, high-frequency oscillations in the brightness of small stars are the most difficult to measure. This is why most objects previously subjected to asteroseismic analysis are larger than the sun.


With the very high precision of the Kepler instrument, astronomers have reached a new milestone. The star Kepler-37, with a radius just three-quarters of the sun, now is the smallest bell in the asteroseismology steeple. The radius of the star is known to three percent accuracy, which translates to exceptional accuracy in the planet's size.


Ames is responsible for Kepler's ground system development, mission operations, and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development.


Ball Aerospace & Technologies Corp. in Boulder, Colo., 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 tenth Discovery Mission and was funded by NASA's Science Mission Directorate at the agency's headquarters in Washington.


For more information about the Kepler mission, visit: http://www.nasa.gov/kepler .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


J.D. Harrington 202-358-5241

Headquarters, Washington

j.d.harrington@nasa.gov


2013-066
Posted by Nelio Inacio at 5:52 AM 0 comments

NASA and JPL Contribute to European Jupiter Mission

NASA and JPL Contribute to European Jupiter Mission:

The JUpiter ICy moons Explorer mission, JUICE
The JUpiter ICy moons Explorer mission, JUICE (Artist impression ) Image credit: ESA/AOES

› Larger image

February 21, 2013

NASA has selected key contributions to a 2022 European Space Agency (ESA) mission that will study Jupiter and three of its largest moons in unprecedented detail. The moons are thought to harbor vast water oceans beneath their icy surfaces.


NASA's contribution will consist of one U.S.-led science instrument and hardware for two European instruments to fly on ESA's Jupiter Icy Moons Explorer (JUICE) mission. Jeffrey Plaut of NASA's Jet Propulsion Laboratory in Pasadena, Calif., will be the U.S. lead for the Radar for Icy Moon Exploration experiment. The radar experiment's principal investigator is Lorenzo Bruzzone of Universita degli Studi di Trento in Italy.


Under the lead of Bruzzone and the Italian Space Agency, JPL will provide the transmitter and receiver hardware for a radar sounder designed to penetrate the icy crust of Jupiter's moons Europa, Ganymede and Callisto to a depth of about 5 miles (9 kilometers). This will allow scientists to see for the first time the underground structure of these tectonically complex and unique icy worlds.


JUICE will carry 11 experiments developed by scientific teams from 15 European countries, the United States and Japan.


The spacecraft will orbit Jupiter for three years and travel past Callisto and Europa multiple times, then orbit Ganymede, a moon larger than the planet Mercury. JUICE will conduct the first thorough exploration of Jupiter since NASA's Galileo mission from 1989-2003.


By studying the Jupiter system, JUICE will look to learn more about the formation and evolution of potentially habitable worlds in our solar system and beyond.


"NASA is thrilled to collaborate with ESA on this exciting mission to explore Jupiter and its icy moons," said John Grunsfeld, NASA's associate administrator for science in Washington. "Working together with ESA and our other international partners is key to enabling future scientific progress in our quest to understand the cosmos."


The solar-powered spacecraft will carry cameras and spectrometers, a laser altimeter and an ice-penetrating radar instrument. The mission also will carry a magnetometer, plasma and particle monitors, and radio science hardware. The spacecraft is scheduled to arrive at the Jupiter system in 2030.


"The selection of JUICE's instruments is a key milestone in ESA's flagship mission to the outer solar system, which represents an unprecedented opportunity to showcase leading European technological and scientific expertise," said Alvaro Gimenez Canete, ESA's director of science and robotic exploration.


NASA invited researchers in 2012 to submit proposals for NASA-provided instruments for the mission. Nine were reviewed, with one selected to fly. NASA agreed to provide critical hardware for two of the 10 selected European-led instruments. NASA's total contribution to the JUICE mission is $100 million for design, development and operation of the instruments through 2033.


In addition to the radar team and instrument, the NASA contributions are:


-- Ultraviolet Spectrometer: The principal investigator is Randy Gladstone of Southwest Research Institute in San Antonio. This spectrometer will acquire images to explore the surfaces and atmospheres of Jupiter's icy moons and how they interact with the Jupiter environment. The instrument also will determine how Jupiter's upper atmosphere interacts with its lower atmosphere below, and the ionosphere and magnetosphere above. The instrument will provide images of the aurora on Jupiter and Ganymede.


-- Particle Environment Package: The principal investigator is Stas Barabash of the Swedish Institute of Space Physics. The U.S. lead is Pontus Brandt of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md. Under the lead of Barabash and the Swedish National Space Board, APL will provide instruments to this suite to measure the neutral material and plasma that are accelerated and heated to extreme levels in Jupiter's fierce and complex magnetic environment.


NASA's Science Mission Directorate conducts a wide variety of research and scientific exploration programs for Earth studies, space weather, the solar system and the universe. The New Frontiers Program Office at NASA's Marshall Space Flight Center in Huntsville, Ala., will manage the NASA contributions. JUICE is the first large-class mission in ESA's Cosmic Vision 2015-2025 Program.


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


For more information about the JUICE mission, visit: http://sci.esa.int/juice .

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Dwayne C. Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov


2013-069
Posted by Nelio Inacio at 5:51 AM 0 comments

Tuesday, July 29, 2014

NASA and JPL Contribute to European Jupiter Mission

NASA and JPL Contribute to European Jupiter Mission:

The JUpiter ICy moons Explorer mission, JUICE
The JUpiter ICy moons Explorer mission, JUICE (Artist impression ) Image credit: ESA/AOES
› Larger image

February 21, 2013

NASA has selected key contributions to a 2022 European Space Agency (ESA) mission that will study Jupiter and three of its largest moons in unprecedented detail. The moons are thought to harbor vast water oceans beneath their icy surfaces.


NASA's contribution will consist of one U.S.-led science instrument and hardware for two European instruments to fly on ESA's Jupiter Icy Moons Explorer (JUICE) mission. Jeffrey Plaut of NASA's Jet Propulsion Laboratory in Pasadena, Calif., will be the U.S. lead for the Radar for Icy Moon Exploration experiment. The radar experiment's principal investigator is Lorenzo Bruzzone of Universita degli Studi di Trento in Italy.


Under the lead of Bruzzone and the Italian Space Agency, JPL will provide the transmitter and receiver hardware for a radar sounder designed to penetrate the icy crust of Jupiter's moons Europa, Ganymede and Callisto to a depth of about 5 miles (9 kilometers). This will allow scientists to see for the first time the underground structure of these tectonically complex and unique icy worlds.


JUICE will carry 11 experiments developed by scientific teams from 15 European countries, the United States and Japan.


The spacecraft will orbit Jupiter for three years and travel past Callisto and Europa multiple times, then orbit Ganymede, a moon larger than the planet Mercury. JUICE will conduct the first thorough exploration of Jupiter since NASA's Galileo mission from 1989-2003.


By studying the Jupiter system, JUICE will look to learn more about the formation and evolution of potentially habitable worlds in our solar system and beyond.


"NASA is thrilled to collaborate with ESA on this exciting mission to explore Jupiter and its icy moons," said John Grunsfeld, NASA's associate administrator for science in Washington. "Working together with ESA and our other international partners is key to enabling future scientific progress in our quest to understand the cosmos."


The solar-powered spacecraft will carry cameras and spectrometers, a laser altimeter and an ice-penetrating radar instrument. The mission also will carry a magnetometer, plasma and particle monitors, and radio science hardware. The spacecraft is scheduled to arrive at the Jupiter system in 2030.


"The selection of JUICE's instruments is a key milestone in ESA's flagship mission to the outer solar system, which represents an unprecedented opportunity to showcase leading European technological and scientific expertise," said Alvaro Gimenez Canete, ESA's director of science and robotic exploration.


NASA invited researchers in 2012 to submit proposals for NASA-provided instruments for the mission. Nine were reviewed, with one selected to fly. NASA agreed to provide critical hardware for two of the 10 selected European-led instruments. NASA's total contribution to the JUICE mission is $100 million for design, development and operation of the instruments through 2033.


In addition to the radar team and instrument, the NASA contributions are:


-- Ultraviolet Spectrometer: The principal investigator is Randy Gladstone of Southwest Research Institute in San Antonio. This spectrometer will acquire images to explore the surfaces and atmospheres of Jupiter's icy moons and how they interact with the Jupiter environment. The instrument also will determine how Jupiter's upper atmosphere interacts with its lower atmosphere below, and the ionosphere and magnetosphere above. The instrument will provide images of the aurora on Jupiter and Ganymede.


-- Particle Environment Package: The principal investigator is Stas Barabash of the Swedish Institute of Space Physics. The U.S. lead is Pontus Brandt of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md. Under the lead of Barabash and the Swedish National Space Board, APL will provide instruments to this suite to measure the neutral material and plasma that are accelerated and heated to extreme levels in Jupiter's fierce and complex magnetic environment.


NASA's Science Mission Directorate conducts a wide variety of research and scientific exploration programs for Earth studies, space weather, the solar system and the universe. The New Frontiers Program Office at NASA's Marshall Space Flight Center in Huntsville, Ala., will manage the NASA contributions. JUICE is the first large-class mission in ESA's Cosmic Vision 2015-2025 Program.


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


For more information about the JUICE mission, visit: http://sci.esa.int/juice .

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Dwayne C. Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov


2013-069
Posted by Nelio Inacio at 5:56 AM 0 comments

NASA Hosts Media Teleconference About Black Hole Studies

NASA Hosts Media Teleconference About Black Hole Studies:

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

› Full image and caption

February 25, 2013

PASADENA, Calif. -- NASA will host a news teleconference at 10 a.m. PST (1 p.m. EST), Wednesday, Feb. 27, to announce black hole observations from its newest X-ray telescope, the Nuclear Spectroscopic Telescope Array (NuSTAR), and the European Space Agency's XMM-Newton X-ray telescope.


The briefing participants are:


-- Fiona Harrison, NuSTAR principal investigator, California Institute of Technology, Pasadena, Calif.

-- Guido Risaliti, astronomer, Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.

-- Arvind Parmar, head of Astrophysics and Fundamental Physics Missions Division, European Space Agency


Visuals will be posted at the start of the teleconference on NASA's NuSTAR site: http://www.nasa.gov/NuSTAR .


Audio of the teleconference will be streamed live on NASA's website at: http://www.nasa.gov/newsaudio .


Audio and visuals will be streamed live online at: http://www.ustream.tv/nasajpl2 .


For more information about NuSTAR, visit: http://www.nasa.gov/NuSTAR . For more information about the European Space Agency's XMM-Newton X-ray telescope, visit: http://www.esa.int/Our_Activities/Space_Science/XMM-Newton_overview .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


J.D. Harrington 202-358-5241

Headquarters, Washington

j.d.harrington@nasa.gov


2013-071
Posted by Nelio Inacio at 5:55 AM 0 comments

NASA Announces New CubeSat Space Mission Candidates

NASA Announces New CubeSat Space Mission Candidates:

Artist's concept of the Interplanetary NanoSpacecraft Pathfinder In Relevant Environment (INSPIRE) CubeSat project.
Artist's concept of the Interplanetary NanoSpacecraft Pathfinder In Relevant Environment (INSPIRE) CubeSat project. The dual INSPIRE CubeSats, the world's first CubeSats to launched beyond Earth orbit, will demonstrate functionality, communication, navigation and payload hosting in interplanetary space. INSPIRE is a NASA JPL partnership with the University of Michigan, Ann Arbor; Cal Poly San Luis Obispo; and the University of Texas at Austin, in collaboration with Goldstone-Apple Valley Radio Telescope.
Image credit: NASA/JPL-Caltech

› Larger image

February 26, 2013

PASADENA, Calif. - NASA has selected 24 small satellites, including three from NASA's Jet Propulsion Laboratory in Pasadena, Calif., to fly as auxiliary payloads aboard rockets planned to launch in 2014, 2015 and 2016. The proposed CubeSats come from universities across the country, a Florida high school, several non-profit organizations and NASA field centers.


CubeSats belong to a class of research spacecraft called nanosatellites. The cube-shaped satellites measure about 4 inches (10 centimeters) on each side, have a volume of about 1 quart (1 liter), and weigh less than 3 pounds (1.1 kilograms).


The selections are from the fourth round of the CubeSat Launch Initiative. After launch, the satellites will conduct technology demonstrations, educational research or science missions. The selected CubeSats will be eligible for flight after final negotiations and an opportunity for flight becomes available.


The following organizations submitted winning satellite proposals:


-- The Aerospace Corporation, El Segundo, Calif.

-- The Discovery Museum and Planetarium, Bridgeport, Conn.

-- Embry-Riddle Aeronautical University, Prescott, Ariz.

-- Morehead State University, Morehead, Ky., in partnership with the University of California at Berkeley

-- Montana State University, Bozeman (two CubeSats) in partnership with The University of New Hampshire, Durham

-- Merritt Island High School, Fla., in partnership with California Polytechnic State University, San Luis Obispo

-- NASA's Ames Research Center, Moffett Field, Calif.

-- NASA's Goddard Space Flight Center, Greenbelt, Md. (three CubeSats)

-- NASA's Jet Propulsion Laboratory, Pasadena, Calif. (three CubeSats)

-- NASA's Kennedy Space Center, Fla.

-- Pennsylvania State University, in partnership with the Naval Research Laboratory, Monterey, Calif.; and The Aerospace Corporation, El Segundo, Calif.

-- Saint Louis University, St. Louis, Mo.

-- Tyvak Nano-Satellites Systems, Irvine, Calif., in partnership with the California Polytechnic State University, San Luis Obispo

-- University at Buffalo, The State University of New York

-- University of Colorado, Boulder

-- University of Florida, Gainesville, in partnership with Stanford University

-- University of Maryland, Baltimore County

-- University of Texas, Austin

-- Vanderbilt University, Nashville, Tenn., in partnership with the Radio Amateur Satellite Corporation, Silver Spring, Md.


The three CubeSats from JPL, which is managed for NASA by the California Institute of Technology in Pasadena, are:


--The Integrated Solar Array and Reflectarray Antenna (ISARA), a technology demonstration of a practical, low-cost Ka-band high-gain antenna on a 3U CubeSat that will increase downlink data rates from a baseline of 9.6 kilobits per second to more than 100 megabits per second with minimal impact on spacecraft mass, volume, cost and power requirements.


--The CubeSat VHF transmitter to study Ionospheric dispersion of Radio Pulses (CHIRP), a 6U CubeSat designed to provide measurements of very high frequency (VHF) radio pulses propagated through the ionosphere that will be essential to the development of SWORD, a future explorer class charged-particle astronomical observatory.


--The Interplanetary NanoSpacecraft Pathfinder In Relevant Environment (INSPIRE) project, which will open deep-space heliophysics and planetary science to the CubeSat community by demonstrating functionality, communication, navigation and payload-hosting in interplanetary space on dual 3U CubeSats.


In the three previous rounds of the CubeSat initiative, NASA has selected 63 missions for flight. The agency's Launch Services Program Educational Launch of Nanosatellite (ELaNa) Program has launched 12 CubeSat missions. This year, 22 CubeSat missions are scheduled for flight.


For additional information on NASA's CubeSat Launch Initiative program, visit:
http://go.nasa.gov/nXOuPI .


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

Jane Platt 818-354-0880

Jet Propulsion Laboratory, Pasadena, Calif.

Jane.platt@jpl.nasa.gov


Joshua Buck 202-357-1100

NASA Headquarters, Washington

Jbuck@nasa.gov


2013-073
Posted by Nelio Inacio at 5:55 AM 0 comments

NASA's Aquarius Sees Salty Shifts

NASA's Aquarius Sees Salty Shifts:

NASA has released the first full year of validated ocean surface salinity data from the agency's Aquarius
NASA has released the first full year of validated ocean surface salinity data from the agency's Aquarius instrument aboard the Aquarius/SAC-D spacecraft. The data cover the period from Dec. 2011 through Dec. 2012. Red colors represent areas of high salinity, while blue shades represent areas of low salinity. Among the prominent salinity features visible in this view are the large area of highly saline water across the North Atlantic. This area, the saltiest anywhere in the open ocean, is analogous to deserts on land, where little rainfall and much evaporation occur. Aquarius is a focused effort to measure ocean surface salinity and will provide the global view of salinity variability needed for climate studies. The mission is a collaboration between NASA and the Space Agency of Argentina (Comisión Nacional de Actividades Espaciales).
Image credit: NASA/GSFC/JPL-Caltech

› Larger image


February 27, 2013

The colorful images chronicle the seasonal stirrings of our salty world: Pulses of freshwater gush from the Amazon River's mouth; an invisible seam divides the salty Arabian Sea from the fresher waters of the Bay of Bengal; a large patch of freshwater appears in the eastern tropical Pacific in the winter. These and other changes in ocean salinity patterns are revealed by the first full year of surface salinity data captured by NASA's Aquarius instrument.


"With a bit more than a year of data, we are seeing some surprising patterns, especially in the tropics," said Aquarius Principal Investigator Gary Lagerloef, of Earth & Space Research in Seattle. "We see features evolve rapidly over time."


Launched June 10, 2011, aboard the Argentine spacecraft Aquarius/Satelite de Aplicaciones Cientificas (SAC)-D, Aquarius is NASA's first satellite instrument specifically built to study the salt content of ocean surface waters. Salinity variations, one of the main drivers of ocean circulation, are closely connected with the cycling of freshwater around the planet and provide scientists with valuable information on how the changing global climate is altering global rainfall patterns.


The salinity sensor detects the microwave emissivity of the top approximately 1 inch (1 to 2 centimeters) of ocean water - a physical property that varies depending on temperature and saltiness. The instrument collects data in 240-mile-wide (386 kilometers) swaths in an orbit designed to obtain a complete survey of global salinity of ice-free oceans every seven days.


The Changing Ocean


The animated version of Aquarius' first year of data unveils a world of varying salinity patterns. The Arabian Sea, nestled up against the dry Middle East, appears much saltier than the neighboring Bay of Bengal, which gets showered by intense monsoon rains and receives freshwater discharges from the Ganges and other large rivers. Another mighty river, the Amazon, releases a large freshwater plume that heads east toward Africa or bends up north to the Caribbean, depending on the prevailing seasonal currents. Pools of freshwater carried by ocean currents from the central Pacific Ocean's regions of heavy rainfall pile up next to Panama's coast, while the Mediterranean Sea sticks out in the Aquarius maps as a very salty sea.


One of the features that stands out most clearly is a large patch of highly saline water across the North Atlantic. This area, the saltiest anywhere in the open ocean, is analogous to deserts on land, where little rainfall and a lot of evaporation occur. A NASA-funded expedition, the Salinity Processes in the Upper Ocean Regional Study (SPURS), traveled to the North Atlantic's saltiest spot last fall to analyze the causes behind this high salt concentration and to validate Aquarius measurements.


"My conclusion after five weeks out at sea and analyzing five weekly maps of salinity from Aquarius while we were there was that indeed, the patterns of salinity variation seen from Aquarius and by the ship were similar," said Eric Lindstrom, NASA's physical oceanography program scientist, NASA Headquarters, Washington, and a participant of the SPURS research cruise.


Future Goals


"The Aquarius prime mission is scheduled to run for three years but there is no reason to think that the instrument could not be able to provide valuable data for much longer than that," said Gene Carl Feldman, Aquarius project manager at NASA's Goddard Space Flight Center in Greenbelt, Md. "The instrument has been performing flawlessly and our colleagues in Argentina are doing a fantastic job running the spacecraft, providing us a nice, stable ride."


In future years, one of the main goals of the Aquarius team is to figure out ways to fine-tune the readings and retrieve data closer to the coasts and the poles. Land and ice emit very bright microwave emissions that swamp the signal read by the satellite. At the poles, there's the added complication that cold polar waters require very large changes in their salt concentration to modify their microwave signal.


Still, the Aquarius team was surprised by how close to the coast the instrument is already able to collect salinity measurements.


"The fact that we're getting areas, particularly around islands in the Pacific, that are not obviously badly contaminated is pretty remarkable. It says that our ability to screen out land contamination seems to be working quite well," Feldman said.


Another factor that affects salinity readings is intense rainfall. Heavy rain can affect salinity readings by attenuating the microwave signal Aquarius reads off the ocean surface as it travels through the soaked atmosphere. Rainfall can also create roughness and shallow pools of freshwater on the ocean surface. In the future, the Aquarius team wants to use another instrument aboard Aquarius/SAC-D, the Argentine-built Microwave Radiometer, to gauge the presence of intense rain simultaneously to salinity readings, so that scientists can flag data collected during heavy rainfall.


An ultimate goal is combining the Aquarius measurements with those of its European counterpart, the Soil Moisture and Ocean Salinity satellite (SMOS) to produce more accurate and finer maps of ocean salinity. In addition, the Aquarius team, in collaboration with researchers at the U.S. Department of Agriculture, is about to release its first global soil moisture dataset, which will complement SMOS' soil moisture measurements.


"The first year of the Aquarius mission has mostly been about understanding how the instruments and algorithms are performing," Feldman said. "Now that we have overcome the major hurdles, we can really begin to focus on understanding what the data are telling us about how the ocean works, how it affects weather and climate, and what new insights we can gain by having these remarkable salinity measurements."


Aquarius was built by NASA's Jet Propulsion Laboratory, Pasadena, Calif.; and NASA Goddard. JPL managed Aquarius through its commissioning phase and is archiving mission data. Goddard now manages Aquarius mission operations and processes science data. Argentina's space agency, Comision Nacional de Actividades Espaciales (CONAE), provided the SAC-D spacecraft, optical camera, thermal camera with Canada, microwave radiometer, sensors from various Argentine institutions and the mission operations center. France and Italy also contributed instruments. For more information about NASA's Aquarius mission, visit: http://www.nasa.gov/aquarius .


For a narrated global tour of Aquarius ocean surface salinity measurements, see: http://www.youtube.com/watch?v=5xQP_B18vMw . A visualization showing changes in global ocean surface salinity as measured by Aquarius from Dec. 2011 through Dec. 2012 can be seen at: http://www.youtube.com/watch?v=RJVnZnZUUYc .

Written by Maria-José Viñas


Media contact:
Alan Buis 818-354-0474

NASA Jet Propulsion Laboratory, Pasadena, Calif.

Alan.buis@jpl.nasa.gov


2013-074
Posted by Nelio Inacio at 5:53 AM 0 comments

What Lies Beneath: NASA Antarctic Sub Goes Subglacial

What Lies Beneath: NASA Antarctic Sub Goes Subglacial:

A video camera on a NASA-designed-and-funded mini-submarine captured this view as it descended a 2,600-foot-deep
A video camera on a NASA-designed-and-funded mini-submarine captured this view as it descended a 2,600-foot-deep (800-meter-deep) borehole to explore Antarctica's subglacial Lake Whillans. The international Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project was designed to gain insights into subglacial biology, climate history and modern ice sheet behavior. Image credit: NASA/JPL-Caltech
› Larger image

February 28, 2013

When researcher Alberto Behar from NASA's Jet Propulsion Laboratory in Pasadena, Calif., joined an international Antarctic expedition last month on a trek to investigate a subglacial lake, he brought with him a unique instrument designed and funded by NASA to help the researchers study one of the last unexplored aquatic environments on Earth.


Called the Micro-Submersible Lake Exploration Device, the instrument was a small robotic sub about the size and shape of a baseball bat. Designed to expand the range of extreme environments accessible by humans while minimally disturbing the environment, the sub was equipped with hydrological chemical sensors and a high-resolution imaging system. The instruments and cameras characterize the geology, hydrology and chemical characteristics of the sub's surroundings. Behar supervised a team of students from Arizona State University, Tempe, in designing, developing, testing and operating the first-of-its-kind sub.


"This is the first instrument ever to explore a subglacial lake outside of a borehole," Behar said. "It's able to take us places that are inaccessible by any other instruments in existence."


The sub was deployed by the U.S. team of the international Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project. The project's objective was to access subglacial Lake Whillans, located more than 2,000 feet (610 meters) below sea level, deep within West Antarctica's Ross Ice Shelf, nearly 700 miles (about 1,125 kilometers) from the U.S. McMurdo Station. The 20-square-mile (50-square-kilometer) lake is totally devoid of sunlight and has a temperature of 31 degrees Fahrenheit (minus 0.5 degrees Celsius). It is part of a vast Antarctic subglacial aquatic system that covers an area about the size of the continental United States.


The WISSARD team included researchers from eight U.S. universities and two collaborating international institutions. They used specialized tools to get clean samples of subglacial lake water and sediments, survey the lake floor with video and characterize the biological, chemical and physical properties of the lake and its surroundings. Their research is designed to gain insights into subglacial biology, climate history and modern ice sheet behavior.


The instrument consists of a "mothership" connected to a deployment device that houses the submarine. The sub is designed to operate at depths of up to three-quarters of a mile (1.2 kilometers) and within a range of 0.6 miles (1 kilometer) from the bottom of the borehole that was drilled through the ice to reach the lake. It transmits real-time high-resolution imagery, salinity, temperature and depth measurements to the surface via fiber-optic cables.


In a race against time and the elements to access the lake before the end of the current Antarctic field season, the WISSARD team spent three days in January drilling a 2,600-foot-deep (800-meters), 20-inch-wide (50-centimeters) borehole into the lake, which they reached on Jan. 28.


Like Alice down the rabbit hole, the sub was then sent down the borehole, where it was initially used to guide drilling operations. When the instrument finally reached the lake, the team used its imagery to survey the lake floor. The data enabled the team to verify that the rest of the project's instruments could be safely deployed into the lake. The WISSARD team was then able to proceed with its next phase: collecting lake water samples to search for microbial life.


And that search has apparently paid off. Earlier this month, the team reported that the lake water did indeed contain living bacteria, a discovery that might hold important implications for the search for life elsewhere in the universe.


To learn more about the expedition, watch this short video narrated by Behar: http://www.jpl.nasa.gov/video/?id=1201 .


Core funding for WISSARD and the Micro-Submersible Lake Exploration Device was provided by the National Science Foundation-Office of Polar Programs. The sub was funded by NASA's Cryospheric Sciences and Astrobiology programs. Additional funds for WISSARD instrument development were provided by the National Oceanic and Atmospheric Administration and the Gordon and Betty Moore Foundation.


For more on WISSARD, visit: http://www.wissard.org . For more on Behar's previous robotic Antarctic research, visit: http://www.nasa.gov/topics/earth/features/antarctic-shrimp.html .

Alan Buis 818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

alan.buis@jpl.nasa.gov


2013-077
Posted by Nelio Inacio at 5:52 AM 0 comments
Subscribe to: Posts (Atom)