Wednesday, July 30, 2014

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

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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

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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

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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
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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

Cassini Spies Bright Venus From Saturn Orbit

Cassini Spies Bright Venus From Saturn Orbit:

Earth's Twin Seen From Saturn
Peering over the shoulder of giant Saturn, through its rings, and across interplanetary space, NASA's Cassini spacecraft spies the bright, cloudy terrestrial planet, Venus. The vast distance from Saturn means that Venus only shows up as a white dot, just above and to the right of the image center. Image credit: NASA/JPL-Caltech/Space Science Institute
› Full image and caption

March 01, 2013

PASADENA, Calif. - A distant world gleaming in sunlight, Earth's twin planet, Venus, shines like a bright beacon in images taken by NASA's Cassini spacecraft in orbit around Saturn.


One special image of Venus and Saturn was taken last November when Cassini was placed in the shadow of Saturn. This allowed Cassini to look in the direction of the sun and Venus, and take a backlit image of Saturn and its rings in a particular viewing geometry called "high solar phase." This observing position reveals details about the rings and Saturn's atmosphere that cannot be seen in lower solar phase.


One of the Venus and Saturn images being released today is a combination of separate red, green and blue images covering the planet and main rings and processed to produce true color. Last December, a false-color version of the mosaic was released.


Another image, taken in January, captures Venus just beyond the limb of Saturn and in close proximity to Saturn's G ring, a thin ring just beyond the main Saturnian rings. The diffuse E ring, which is outside the G ring and created by the spray of the moon Enceladus, also is visible.


These images can be found at http://www.nasa.gov/mission_pages/cassini/multimedia/pia14935.html and http://www.nasa.gov/mission_pages/cassini/multimedia/pia14936.html.


Venus is, along with Mercury, Earth and Mars, one of the rocky "terrestrial" planets in the solar system that orbit relatively close to the sun. Though Venus has an atmosphere of carbon dioxide that reaches nearly 900 degrees Fahrenheit (500 degrees Celsius) and a surface pressure 100 times that of Earth's, it is considered a twin to our planet because of their similar sizes, masses, rocky compositions and close orbits. It is covered in thick sulfuric acid clouds, making it very bright.


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


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

Jia-Rui Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Steve Mullins 720-974-5859

Space Science Institute, Boulder, Colo.

media@ciclops.org


2013-079
Posted by Nelio Inacio at 5:52 AM 0 comments

Comet to Make Close Flyby of Red Planet in October 2014

Comet to Make Close Flyby of Red Planet in October 2014:

This computer graphic depicts the orbit of comet 2013 A1 (Siding Spring) through the inner solar system.
This computer graphic depicts the orbit of comet 2013 A1 (Siding Spring) through the inner solar system.
Image credit: NASA/JPL-Caltech
› Larger image

March 05, 2013

Comet 2013 A1 (Siding Spring) will make a very close approach to Mars in October 2014.


The latest trajectory of comet 2013 A1 (Siding Spring) generated by the Near-Earth Object Program Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif., indicates the comet will pass within 186,000 miles (300,000 kilometers) of Mars and there is a strong possibility that it might pass much closer. The NEO Program Office's current estimate based on observations through March 1, 2013, has it passing about 31,000 miles (50,000 kilometers) from the Red Planet's surface. That distance is about two-and-a-half times that of the orbit of outermost moon, Deimos.


Scientists generated the trajectory for comet Siding Spring based on the data obtained by observations since October 2012. Further refinement to its orbit is expected as more observational data is obtained. At present, Mars lies within the range of possible paths for the comet and the possibility of an impact cannot be excluded. However, since the impact probability is currently less than one in 600, future observations are expected to provide data that will completely rule out a Mars impact.


During the close Mars approach the comet will likely achieve a total visual magnitude of zero or brighter, as seen from Mars-based assets. From Earth, the comet is not expected to reach naked eye brightness, but it may become bright enough (about magnitude 8) that it could be viewed from the southern hemisphere in mid-September 2014, using binoculars, or small telescopes.


Scientists at the Near-Earth Object Program Office estimate that comet Siding Spring has been on a more than a million-year journey, arriving from our solar system's distant Oort cloud. The comet could be complete with the volatile gases that short period comets often lack due to their frequent returns to the sun's neighborhood.


Rob McNaught discovered comet 2013 A1 Siding Spring on Jan. 3, 2013, at Siding Spring Observatory in Australia. A study of germane archival observations has unearthed more images of the comet, extending the observation interval back to Oct. 4, 2012.


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


2013-081
Posted by Nelio Inacio at 5:51 AM 0 comments

A Window into Europa's Ocean Right at the Surface

A Window into Europa's Ocean Right at the Surface:

Taste of the Ocean on Europa's Surface
Based on new evidence from Jupiter's moon Europa, astronomers hypothesize that chloride salts bubble up from the icy moon's global liquid ocean and reach the frozen surface where they are bombarded with sulfur from volcanoes on Jupiter's innermost large moon Io. Image credit: NASA/JPL-Caltech
› Full image and caption

March 05, 2013

If you could lick the surface of Jupiter's icy moon Europa, you would actually be sampling a bit of the ocean beneath. A new paper by Mike Brown, an astronomer at the California Institute of Technology in Pasadena, Calif., and Kevin Hand from NASA's Jet Propulsion Laboratory, also in Pasadena, details the strongest evidence yet that salty water from the vast liquid ocean beneath Europa's frozen exterior actually makes its way to the surface.


The finding, based on some of the best data of its kind since NASA's Galileo mission (1989 to 2003) to study Jupiter and its moons, suggests there is a chemical exchange between the ocean and surface, making the ocean a richer chemical environment. The work is described in a paper that has been accepted for publication in the Astronomical Journal.


The exchange between the ocean and the surface, Brown said, "means that energy might be going into the ocean, which is important in terms of the possibilities for life there. It also means that if you'd like to know what's in the ocean, you can just go to the surface and scrape some off."


Europa's ocean is thought to cover the moon's whole globe and is about 60 miles (100 kilometers) thick under a thin ice shell. Since the days of NASA's Voyager and Galileo missions, scientists have debated the composition of Europa's surface. The infrared spectrometer aboard Galileo was not capable of providing the detail needed to identify definitively some of the materials present on the surface. Now, using the Keck II Telescope on Mauna Kea, Hawaii, and its OSIRIS spectrometer, Brown and Hand have identified a spectroscopic feature on Europa's surface that indicates the presence of a magnesium sulfate salt, a mineral called epsomite, that could have formed by oxidation of a mineral likely originating from the ocean below.


Brown and Hand started by mapping the distribution of pure water ice versus anything else. The spectra showed that even Europa's leading hemisphere contains significant amounts of non-water ice. Then, at low latitudes on the trailing hemisphere-the area with the greatest concentration of the non-water ice material-they found a tiny, never-before-detected dip in the spectrum.


The two researchers tested everything from sodium chloride to Drano in Hand's lab at JPL, where he tries to simulate the environments found on various icy worlds. At the end of the day, the signature of magnesium sulfate persisted.


The magnesium sulfate appears to be generated by the irradiation of sulfur ejected from the Jovian moon Io and, the authors deduce, magnesium chloride salt originating from Europa's ocean. Chlorides such as sodium and potassium chlorides, which are expected to be on the Europa surface, are in general not detectable because they have no clear infrared spectral features. But magnesium sulfate is detectable. The authors believe the composition of Europa's ocean may closely resemble the salty ocean of Earth.


Europa is considered a premier target in the search for life beyond Earth, Hand said. A NASA-funded study team led by JPL and the Johns Hopkins University Applied Physics Laboratory, Laurel, Md., has been working with the scientific community to identify options to explore Europa further. "If we've learned anything about life on Earth, it's that where there's liquid water, there's generally life," Hand said. "And of course our ocean is a nice, salty ocean. Perhaps Europa's salty ocean is also a wonderful place for life."


The work was supported, in part, by the NASA Astrobiology Institute through the Icy Worlds team based at JPL, a division of Caltech. The NASA Astrobiology Institute, based at NASA's Ames Research Center, Moffett Field, Calif., is a partnership among NASA, 15 U.S. teams, and 13 international consortia. The NAI is part of NASA's Astrobiology program, which supports research into the origin, evolution, distribution and future of life on Earth and the potential for life elsewhere.

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Brian Bell 626-395-5832

California Institute of Technology

bbell2@caltech.edu


2009-082
Posted by Nelio Inacio at 5:50 AM 0 comments

Comet PANSTARRS Rises to the Occasion Mid-March

Comet PANSTARRS Rises to the Occasion Mid-March:

For those in search of comet L4 PANSTARRS, look to the west after sunset in early and mid-March.
For those in search of comet L4 PANSTARRS, look to the west after sunset in early and mid-March. This graphic shows the comet's expected positions in the sky. Image credit: NASA
› Larger image

March 07, 2013

Comets visible to the naked eye are a rare delicacy in the celestial smorgasbord of objects in the nighttime sky. Scientists estimate that the opportunity to see one of these icy dirtballs advertising their cosmic presence so brilliantly they can be seen without the aid of a telescope or binoculars happens only once every five to 10 years. That said, there may be two naked-eye comets available for your viewing pleasure this year.


"You might have heard of a comet ISON, which may become a spectacular naked-eye comet later this fall," said Amy Mainzer, the principal investigator of NASA's NEOWISE mission at the Jet Propulsion Laboratory in Pasadena, Calif., and self-described cosmic icy dirtball fan. "But if you have the right conditions you don't have to wait for ISON. Within a few days, comet PANSTARRS will be making its appearance in the skies of the Northern Hemisphere just after twilight."


Discovered in June 2011, comet 2011 L4 (PANSTARRS) bears the name of the telescopic survey that discovered it -- the less than mellifluous sounding "Panoramic Survey Telescope and Rapid Response System" which sits atop the Haleakala volcano in Hawaii.


Since its discovery a year-and-a-half ago, observing comet PANSTARRS has been the exclusive dominion of comet aficionados in the Southern Hemisphere, but that is about to change. As the comet continues its well-understood and safe passage through the inner-solar system, its celestial splendor will be lost to those in the Southern Hemisphere, but found by those up north.


"There is a catch to viewing comet PANSTARRS," said Mainzer. "This one is not that bright and is going to be low on the western horizon, so you'll need a relatively unobstructed view to the southwest at twilight and, of course, some good comet-watching weather."


Well, there is one more issue -- the time of day, or night, to view it.


"Look too early and the sky will be too bright," said Rachel Stevenson, a NASA Postdoctoral Fellow at JPL. "Look too late, the comet will be too low and obstructed by the horizon. This comet has a relatively small window."


By March 8, comet PANSTARRS may be viewable for those with a totally unobstructed view of the western horizon for about 15 minutes after twilight. On March 10, it will make its closest approach to the sun about 28 million miles (45 million kilometers) away. As it continues its nightly trek across the sky, the comet may get lost in the sun's glare but should return and be visible to the naked eye by March 12. As time marches on in the month of March, the comet will begin to fade away slowly, becoming difficult to view (even with binoculars or small telescopes) by month's end. The comet will appear as a bright point of light with its diffuse tail pointing nearly straight up from the horizon like an exclamation point.


What, if any, attraction does seeing a relatively dim naked-eye comet with the naked eye hold for someone who works with them every day, with file after file of high-resolution imagery spilling out on her computer workstation?


"You bet I'm going to go look at it!" said Mainzer. "Comet PanSTARRS may be a little bit of a challenge to find without a pair of binoculars, but there is something intimately satisfying to see it with your own two eyes. If you have a good viewing spot and good weather, it will be like the Sword of Gryffindor, it should present itself to anyone who is worthy."


NASA detects, tracks and characterizes asteroids and comets passing relatively 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 predicts their paths 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, DC. 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 , and on Twitter: @asteroidwatch .

DC Agle (818) 393-9011

Jet Propulsion Laboratory, Pasadena, Calif.

agle@jpl.nasa.gov


2013-088
Posted by Nelio Inacio at 5:49 AM 0 comments

NASA Helps See Buried Mars Flood Channels in 3-D

NASA Helps See Buried Mars Flood Channels in 3-D:

Visualization of Buried Marte Vallis Channels
This illustration schematically shows where the Shallow Radar instrument on NASA's Mars Reconnaissance Orbiter detected flood channels that had been buried by lava flows in the Elysium Planitia region of Mars.
› Full image and caption

March 07, 2013

PASADENA, Calif. -- NASA's Mars Reconnaissance Orbiter has provided images allowing scientists for the first time to create a 3-D reconstruction of ancient water channels below the Martian surface.


The spacecraft took numerous images during the past few years that showed channels attributed to catastrophic flooding in the last 500 million years. During this period, Mars had been otherwise considered cold and dry. These channels are essential to understanding the extent to which recent hydrologic activity prevailed during such arid conditions. They also help scientists determine whether the floods could have induced episodes of climate change.


The estimated size of the flooding appears to be comparable to the ancient mega-flood that created the Channeled Scablands in the Pacific Northwest region of the United States, in eastern Washington.


The findings are reported in the March 7 issue of Science Express by a team of scientists from NASA, the Smithsonian Institution in Washington, and the Southwest Research Institute in Builder, Colo.


"Our findings show the scale of erosion that created the channels previously was underestimated and the channel depth was at least twice that of previous approximations," said Gareth Morgan, a geologist at the National Air and Space Museum's Center for Earth and Planetary Studies in Washington and lead author on the paper. "This work demonstrates the importance of orbital sounding radar in understanding how water has shaped the surface of Mars."


The channels lie in Elysium Planitia, an expanse of plains along the Martian equator and the youngest volcanic region on the planet. Extensive volcanism throughout the last several hundred million years covered most of the surface of Elysium Planitia, and this buried evidence of Mars' older geologic history, including the source and most of the length of the 620-mile-long (1000-kilometer-long) Marte Vallis channel system. To probe the length, width and depth of these underground channels, the researchers used the Mars Reconnaissance Orbiter's Shallow Radar (SHARAD).


Marte Vallis' morphology is similar to more ancient channel systems on Mars, especially those of the Chryse basin. Many scientists think the Chryse channels likely were formed by the catastrophic release of ground water, although others suggest lava can produce many of the same features. In comparison, little is known about Marte Vallis.


With the SHARAD radar, the team was able to map the buried channels in three dimensions with enough detail to see evidence suggesting two different phases of channel formation. One phase etched a series of smaller branching, or "anastomosing," channels that are now on a raised "bench" next to the main channel. These smaller channels flowed around four streamlined islands. A second phase carved the deep, wide channels.


"In this region, the radar picked up multiple 'reflectors,' which are surfaces or boundaries that reflect radio waves, so it was possible to see multiple layers, " said Lynn Carter, the paper's co-author from NASA's Goddard Space Flight Center in Greenbelt, Md. "We have rarely seen that in SHARAD data outside of the polar ice regions of Mars."


The mapping also provided sufficient information to establish the floods that carved the channels originated from a now-buried portion of the Cerberus Fossae fracture system. The water could have accumulated in an underground reservoir and been released by tectonic or volcanic activity.


"While the radar was probing thick layers of dry, solid rock, it provided us with unique information about the recent history of water in a key region of Mars," said co-author Jeffrey Plaut of NASA's Jet Propulsion Laboratory, Pasadena, Calif.


The Italian Space Agency provided the SHARAD instrument on Mars Reconnaissance Orbiter and Sapienza University of Rome leads its operations. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems of Denver built the orbiter and supports its operations.


The 3-D image can be viewed online at: http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA16767.
For more about NASA's Mars Reconnaissance Orbiter mission, visit: http://www.nasa.gov/mro .

Jia-Rui Cook/Guy Webster 818-354-0850/354-6278

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov / guy.webster@jpl.nasa.gov


Dwayne Brown 202-358-1726

NASA Headquarters, Washington

dwayne.c.brown@nasa.gov


Elizabeth Zubritsky 301-614-5438

Goddard Space Flight Center, Greenbelt, Md.

elizabeth.a.zubritsky@nasa.gov


Isabel Lara 202-633-2374

Smithsonian Air and Space Museum, Washington

larai@si.edu


2013-087
Posted by Nelio Inacio at 5:49 AM 0 comments

Cassini Makes Last Close Flyby of Saturnian Moon Rhea

Cassini Makes Last Close Flyby of Saturnian Moon Rhea:

NASA's Cassini spacecraft will be flying close to Saturn's moon Rhea on Saturday
NASA's Cassini spacecraft will be flying close to Saturn's moon Rhea on Saturday, March 9, the last close encounter of Rhea planned for the rest of Cassini's mission. Image credit: NASA/JPL-Caltech
› Larger image

March 07, 2013

NASA's Cassini spacecraft will be swooping close to Saturn's moon Rhea on Saturday, March 9, the last close flyby of Rhea in Cassini's mission. The primary purpose will be to probe the internal structure of the moon by measuring the gravitational pull of Rhea against the spacecraft's steady radio link to NASA's Deep Space Network here on Earth. The results will help scientists understand whether the moon is homogeneous all the way through or whether it has differentiated into the layers of core, mantle and crust.


In addition, Cassini's imaging cameras will take ultraviolet, infrared and visible-light data from Rhea's surface. The cosmic dust analyzer will try to detect any dusty debris flying off the surface from tiny meteoroid bombardments to further scientists' understanding of the rate at which "foreign" objects are raining into the Saturn system.


Cassini will fly within about 600 miles (1,000 kilometers) of the surface. The time of closest approach is around 10:17 a.m. PST (1:17 p.m. EST). This is Cassini's fourth close flyby of Rhea.


On Feb. 10, 2015, Cassini will pass Rhea at about 29,000 miles (47,000 kilometers), but this is not considered a targeted flyby. Cassini has been in orbit around Saturn since 2004 and is in a second mission extension, known as the Solstice mission.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory manages the mission for NASA's Science Mission Directorate, Washington, D.C. JPL is a division of Caltech. For more information on Cassini, visit http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


2013-085

Images

Bombarded Rhea

Cassini looks over the heavily cratered surface of Rhea during the spacecraft's flyby of the moon on March 10, 2012. Image credit:
NASA/JPL-Caltech/Space Science Institute
› Full image and caption

enlarge image



Posted by Nelio Inacio at 5:48 AM 0 comments

Closest Star System Found in a Century

Closest Star System Found in a Century:

Two Brown Dwarfs in Our Backyard
WISE J104915.57-531906 is at the center of the larger image, which was
taken by the NASA's Wide-field Infrared Survey Explorer (WISE). This is the closest star system discovered since 1916, and the third closest to our sun. It is 6.5 light-years away.
› Full image and caption

March 11, 2013

NASA's Wide-field Infrared Survey Explorer (WISE) has discovered a pair of stars that has taken over the title for the third-closest star system to the sun. The duo is the closest star system discovered since 1916.


Both stars in the new binary system are "brown dwarfs," which are stars that are too small in mass to ever become hot enough to ignite hydrogen fusion. As a result, they are very cool and dim, resembling a giant planet like Jupiter more than a bright star like the sun.


"The distance to this brown dwarf pair is 6.5 light-years -- so close that Earth's television transmissions from 2006 are now arriving there," said Kevin Luhman, an associate professor of astronomy and astrophysics at Penn State University, University Park, Pa., and a researcher in Penn State's Center for Exoplanets and Habitable Worlds.


"It will be an excellent hunting ground for planets because the system is very close to Earth, which makes it a lot easier to see any planets orbiting either of the brown dwarfs."


The results will be published in the Astrophysical Journal Letters.


The star system is named "WISE J104915.57-531906" because it was discovered in an infrared map of the entire sky obtained by WISE. It is only slightly farther away than the second-closest star, Barnard's star, which was discovered 6 light-years from the sun in 1916. The closest star system consists of: Alpha Centauri, found to be a neighbor of the sun in 1839 at 4.4 light-years away, and the fainter Proxima Centauri, discovered in 1917 at 4.2 light-years.


Edward (Ned) Wright, the principal investigator for the WISE satellite at UCLA, said, "One major goal when proposing WISE was to find the closest stars to the sun. WISE J1049-5319 is by far the closest star found to date using the WISE data, and the close-up views of this binary system we can get with big telescopes like Gemini and the future James Webb Space Telescope will tell us a lot about the low-mass stars known as brown dwarfs."


The Gemini South telescope in Chile was also used in this study for follow-up observations.


Read the full news release from Penn state at http://science.psu.edu/news-and-events/2013-news/Luhman3-2013 .


WISE completed its all-sky survey in 2011, after surveying the entire sky twice at infrared wavelengths. The maps have been released to the public, but an ongoing project called "AllWISE" will combine data from both sky scans. AllWISE will provide a systematic search across the sky for the nearby moving stars such as WISE J104915.57-531906, and also uncover fainter objects from the distant universe. Those data will be publicly available in late 2013.


NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages, and operated, WISE for NASA's Science Mission Directorate. Edward Wright is the principal investigator and is at UCLA. The mission was selected competitively under NASA's Explorers Program managed by the agency's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah. The spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. 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 is online at http://www.nasa.gov/wise and http://wise.astro.ucla.edu and http://jpl.nasa.gov/wise .

Whitney Clavin 818-354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2013-090
Posted by Nelio Inacio at 5:47 AM 0 comments

'Hot Spots' Ride a Merry-Go-Round on Jupiter

'Hot Spots' Ride a Merry-Go-Round on Jupiter:

Peering Deep into Jupiter's Atmosphere
The dark hot spot in this false-color image from NASA's Cassini spacecraft is a window deep into Jupiter's atmosphere. All around it are layers of higher clouds, with colors indicating which layer of the atmosphere the clouds are in. Image credit: NASA/JPL-Caltech/SSI/GSFC
› Full image and caption

March 14, 2013

In the swirling canopy of Jupiter's atmosphere, cloudless patches are so exceptional that the big ones get the special name "hot spots." Exactly how these clearings form and why they're only found near the planet's equator have long been mysteries. Now, using images from NASA's Cassini spacecraft, scientists have found new evidence that hot spots in Jupiter's atmosphere are created by a Rossby wave, a pattern also seen in Earth's atmosphere and oceans. The team found the wave responsible for the hot spots glides up and down through layers of the atmosphere like a carousel horse on a merry-go-round.


"This is the first time anybody has closely tracked the shape of multiple hot spots over a period of time, which is the best way to appreciate the dynamic nature of these features," said the study's lead author, David Choi, a NASA Postdoctoral Fellow working at NASA's Goddard Space Flight Center in Greenbelt, Md. The paper is published online in the April issue of the journal Icarus.


Choi and his colleagues made time-lapse movies from hundreds of observations taken by Cassini during its flyby of Jupiter in late 2000, when the spacecraft made its closest approach to the planet. The movies zoom in on a line of hot spots between one of Jupiter's dark belts and bright white zones, roughly 7 degrees north of the equator. Covering about two months (in Earth time), the study examines the daily and weekly changes in the sizes and shapes of the hot spots, each of which covers more area than North America, on average.


Much of what scientists know about hot spots came from NASA's Galileo mission, which released an atmospheric probe that descended into a hot spot in 1995. This was the first, and so far only, in-situ investigation of Jupiter's atmosphere.


"Galileo's probe data and a handful of orbiter images hinted at the complex winds swirling around and through these hot spots, and raised questions about whether they fundamentally were waves, cyclones or something in between," said Ashwin Vasavada, a paper co-author who is based at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and who was a member of the Cassini imaging team during the Jupiter flyby. "Cassini's fantastic movies now show the entire life cycle and evolution of hot spots in great detail."


Because hot spots are breaks in the clouds, they provide windows into a normally unseen layer of Jupiter's atmosphere, possibly all the way down to the level where water clouds can form. In pictures, hot spots appear shadowy, but because the deeper layers are warmer, hot spots are very bright at the infrared wavelengths where heat is sensed; in fact, this is how they got their name.


One hypothesis is that hot spots occur when big drafts of air sink in the atmosphere and get heated or dried out in the process. But the surprising regularity of hot spots has led some researchers to suspect there is an atmospheric wave involved. Typically, eight to 10 hot spots line up, roughly evenly spaced, with dense white plumes of cloud in between. This pattern could be explained by a wave that pushes cold air down, breaking up any clouds, and then carries warm air up, causing the heavy cloud cover seen in the plumes. Computer modeling has strengthened this line of reasoning.


From the Cassini movies, the researchers mapped the winds in and around each hot spot and plume, and examined interactions with vortices that pass by, in addition to wind gyres, or spiraling vortices, that merge with the hot spots. To separate these motions from the jet stream in which the hot spots reside, the scientists also tracked the movements of small "scooter" clouds, similar to cirrus clouds on Earth. This provided what may be the first direct measurement of the true wind speed of the jet stream, which was clocked at about 300 to 450 mph (500 to 720 kilometers per hour) -- much faster than anyone previously thought. The hot spots amble at the more leisurely pace of about 225 mph (362 kilometers per hour).


By teasing out these individual movements, the researchers saw that the motions of the hot spots fit the pattern of a Rossby wave in the atmosphere. On Earth, Rossby waves play a major role in weather. For example, when a blast of frigid Arctic air suddenly dips down and freezes Florida's crops, a Rossby wave is interacting with the polar jet stream and sending it off its typical course. The wave travels around our planet but periodically wanders north and south as it goes.


The wave responsible for the hot spots also circles the planet west to east, but instead of wandering north and south, it glides up and down in the atmosphere. The researchers estimate this wave may rise and fall 15 to 30 miles (24 to 50 kilometers) in altitude.


The new findings should help researchers understand how well the observations returned by the Galileo probe extend to the rest of Jupiter's atmosphere. "And that is another step in answering more of the questions that still surround hot spots on Jupiter," said Choi.


The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. The mission is managed by JPL for NASA's Science Mission Directorate, Washington.

Jia-Rui C. Cook 818-354-0850

Jet Propulsion Laboratory, Pasadena, Calif.

jccook@jpl.nasa.gov


Elizabeth Zubritsky 301-614-5438

Goddard Space Flight, Center, Greenbelt, Md.

elizabeth.a.zubritsky@nasa.gov


2013-095
Posted by Nelio Inacio at 5:46 AM 0 comments
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