Dec 18 2014
From The Space Library
NASA, Planetary Scientists Find Meteoritic Evidence of Mars Water Reservoir
NASA and an international team of planetary scientists have found evidence in meteorites on Earth that indicates Mars has a distinct and global reservoir of water or ice near its surface.
Though controversy still surrounds the origin, abundance and history of water on Mars, this discovery helps resolve the question of where the “missing Martian water” may have gone. Scientists continue to study the planet’s historical record, trying to understand the apparent shift from an early wet and warm climate to today’s dry and cool surface conditions.
The reservoir’s existence also may be a key to understanding climate history and the potential for life on Mars. The team’s findings are reported in the journal Earth and Planetary Science Letters.
“There have been hints of a third planetary water reservoir in previous studies of Martian meteorites, but our new data require the existence of a water or ice reservoir that also appears to have exchanged with a diverse set of Martian samples,” said Tomohiro Usui of Tokyo Institute of Technology in Japan, lead author of the paper and a former NASA/Lunar and Planetary Institute postdoctoral fellow. “Until this study there was no direct evidence for this surface reservoir or interaction of it with rocks that have landed on Earth from the surface of Mars.”
Researchers from the Tokyo Institute of Technology, the Lunar and Planetary Institute in Houston, the Carnegie Institution for Science in Washington and NASA’s Astromaterials Research and Exploration Science Division, located at the agency’s Johnson Space Center in Houston, studied three Martian meteorites.
The samples revealed water comprised of hydrogen atoms that have a ratio of isotopes distinct from that found in water in the Red Planet’s mantle and current atmosphere. Isotopes are atoms of the same element with differing numbers of neutrons.
While recent orbiter missions have confirmed the presence of subsurface ice, and melting ground-ice is believed to have formed some geomorphologic features on Mars, this study used meteorites of different ages to show that significant ground water-ice may have existed relatively intact over time.
Researchers emphasize that the distinct hydrogen isotopic signature of the water reservoir must be of sufficient size that it has not reached isotopic equilibrium with the atmosphere.
“The hydrogen isotopic composition of the current atmosphere could be fixed by a quasi-steady-state process that involves rapid loss of hydrogen to space and the sublimation from a widespread ice layer,” said coauthor John Jones, a JSC experimental petrologist and member of NASA’s Mars Curiosity rover team.
Curiosity’s observations in a lakebed, in an area called Mount Sharp, indicate Mars lost its water in a gradual process over a significant period of time.
“In the absence of returned samples from Mars, this study emphasizes the importance of finding more Martian meteorites and continuing to study the ones we have with the ever-improving analytical techniques at our disposal,” said co-author Conel Alexander, a cosmochemist at the Carnegie Institution for Science.
In this investigation, scientists compared water, other volatile element concentrations and hydrogen isotopic compositions of glasses within the meteorites, which may have formed as the rocks erupted to the surface of Mars in ancient volcanic activity or by impact events that hit the Martian surface, knocking them off the planet.
“We examined two possibilities, that the signature for the newly identified hydrogen reservoir either reflects near surface ice interbedded with sediment or that it reflects hydrated rock near the top of the Martian crust,” said coauthor and JSC cosmochemist Justin Simon. “Both are possible, but the fact that the measurements with higher water concentrations appear uncorrelated with the concentrations of some of the other measured volatile elements, in particular chlorine, suggests the hydrogen reservoir likely existed as ice.”
The information being gathered about Mars from studies on Earth, and data being returned from a fleet of robotic spacecraft and rovers on and around the Red Planet, are paving the way for future human missions on a journey to Mars in the 2030s.
RELEASE 14-335 NASA’s Kepler Reborn, Makes First Exoplanet Find of New Mission
NASA's planet-hunting Kepler spacecraft makes a comeback with the discovery of the first exoplanet found using its new mission -- K2.
The discovery was made when astronomers and engineers devised an ingenious way to repurpose Kepler for the K2 mission and continue its search of the cosmos for other worlds.
"Last summer, the possibility of a scientifically productive mission for Kepler after its reaction wheel failure in its extended mission was not part of the conversation," said Paul Hertz, NASA's astrophysics division director at the agency's headquarters in Washington. "Today, thanks to an innovative idea and lots of hard work by the NASA and Ball Aerospace team, Kepler may well deliver the first candidates for follow-up study by the James Webb Space Telescope to characterize the atmospheres of distant worlds and search for signatures of life."
Lead researcher Andrew Vanderburg, a graduate student at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, studied publicly available data collected by the spacecraft during a test of K2 in February 2014. The discovery was confirmed with measurements taken by the HARPS-North spectrograph of the Telescopio Nazionale Galileo in the Canary Islands, which captured the wobble of the star caused by the planet’s gravitational tug as it orbits.
The newly confirmed planet, HIP 116454b, is 2.5 times the diameter of Earth and follows a close, nine-day orbit around a star that is smaller and cooler than our sun, making the planet too hot for life as we know it. HIP 116454b and its star are 180 light-years from Earth, toward the constellation Pisces.
Kepler’s onboard camera detects planets by looking for transits -- when a distant star dims slightly as a planet crosses in front of it. The smaller the planet, the weaker the dimming, so brightness measurements must be exquisitely precise. To enable that precision, the spacecraft must maintain steady pointing. In May 2013, data collection during Kepler's extended prime mission came to an end with the failure of the second of four reaction wheels, which are used to stabilize the spacecraft.
Rather than giving up on the stalwart spacecraft, a team of scientists and engineers crafted a resourceful strategy to use pressure from sunlight as a “virtual reaction wheel” to help control the spacecraft. The resulting K2 mission promises to not only continue Kepler’s planet hunt, but also to expand the search to bright nearby stars that harbor planets that can be studied in detail and better understand their composition. K2 also will introduce new opportunities to observe star clusters, active galaxies and supernovae.
Small planets like HIP 116454b, orbiting nearby bright stars, are a scientific sweet spot for K2 as they are good prospects for follow-up ground studies to obtain mass measurements. Using K2’s size measurements and ground-based mass measurements, astronomers can calculate the density of a planet to determine whether it is likely a rocky, watery or gaseous world.
"The Kepler mission showed us that planets larger in size than Earth and smaller than Neptune are common in the galaxy, yet they are absent in our solar system," said Steve Howell, Kepler/K2 project scientist at NASA's Ames Research Center in Moffett Field, California. "K2 is uniquely positioned to dramatically refine our understanding of these alien worlds and further define the boundary between rocky worlds like Earth and ice giants like Neptune."
Since the K2 mission officially began in May 2014, it has observed more than 35,000 stars and collected data on star clusters, dense star-forming regions, and several planetary objects within our own solar system. It is currently in its third campaign.
The research paper reporting this discovery has been accepted for publication in The Astrophysical Journal.
Ames is responsible for Kepler's mission concept, ground system development, science data analysis and K2 mission operations. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colorado, developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery Mission and was funded by the agency's Science Mission Directorate in Washington.
MEDIA ADVISORY M14-205 NASA, SpaceX Update Launch of Fifth SpaceX Resupply Mission to Space Station
NASA and SpaceX announced today the launch of SpaceX's fifth commercial resupply services mission to the International Space Station now will occur no earlier than Tuesday, Jan. 6.
The new launch date will provide SpaceX engineers time to investigate further issues that arose from a static fire test of the Falcon 9 rocket on Dec. 16 and will avoid beta angle constraints for berthing the Dragon cargo ship to the station that exist through the end of the year.
A beta angle is the position of the sun relative to mechanical structures on the space station. During the time of high beta angles, which run from Dec. 28 through Jan. 7, thermal and operational constraints prohibit Dragon from berthing to the station.
Space station managers will meet Monday, Jan. 5, for a readiness review in advance of the launch attempt Jan. 6. The launch postponement has no impact on the station's crew or its complement of food, fuel and supplies and will not affect the science being delivered to the crew once Dragon arrives at the station.
The launch is scheduled at approximately 6:18 a.m. EST. NASA Television coverage will begin at 5 a.m.
A backup launch attempt is available Wednesday, Jan. 7.
A launch on Jan. 6 will result in a rendezvous and grapple of Dragon Thursday, Jan. 8, at approximately 6 a.m. NASA TV coverage will begin at 4:30 a.m. Installation coverage will begin at 9 a.m.
Prelaunch briefings at NASA's Kennedy Space Center in Florida will be rescheduled for Monday, Jan. 5, with times still to be determined.
RELEASE 14-339 NASA’s Orion Arrives Back at Kennedy, Media Invited to View Spacecraft
After traveling more than 3,600 miles above Earth and 600 miles over sea, NASA’s Orion spacecraft completed the final leg of its journey by land Thursday, arriving home at the agency’s Kennedy Space Center in Florida. Media representatives are invited to attend an event at 10:30 a.m. EST Friday, Dec. 19, marking the arrival.
U.S. media must apply for credentials to attend Friday’s event at Kennedy by 8 a.m. Friday. All media must present two forms of legal, government identification to access Kennedy. One form must be a photo ID, such as a passport or driver's license. Media not previously credentialed for SpaceX CRS-5 will be issued badges at the Kennedy Badging Office, located on State Road 405 east of the Kennedy Space Center Visitor Complex. Journalists must arrive at Kennedy's Press Site by 9:45 a.m. Friday for transportation to the event.
Media accreditation requests must be submitted online at: [[1]]
The deadline for international media to attend in person already has passed.
The spacecraft’s cross-country return, a 2,700 mile road trip from Naval Base San Diego to Kennedy, sets the stage for in-depth analysis of data obtained during Orion’s trip to space and will provide engineers detailed information on how the spacecraft fared during its two-orbit, 4.5-hour flight test, completed on Dec. 5.
“Orion’s flight test was a critical step on our journey to send astronauts to explore deep space destinations,” said Bill Hill, deputy associate administrator for exploration systems development at NASA Headquarters in Washington. “We stressed Orion to help us evaluate its performance and validate our computer models and ground-based evaluations, and the information we gathered will help us improve Orion’s design going forward.”
Data was gathered in real time during the flight test, and more was removed from the vehicle when it arrived on land in San Diego before it was crated for the drive to Florida.
“The flight itself was such a great success, but that’s only the beginning of the story,” said Orion Program Manager Mark Geyer. “Now we get to dig in and really find out if our design performed like we thought it would. This is why we flew the flight. We demonstrated on Dec. 5 that Orion is a very capable vehicle. Now we’re going to keep testing and improving as we begin building the next Orion.”
An initial inspection of the crew module turned up nothing unexpected. There were indications of some micrometeoroid orbital debris strikes on the sides of Orion, which was anticipated.
With the spacecraft back at Kennedy, where it was assembled and prepared for launch, engineers will be able to remove the back shell of the spacecraft and perform inspections of its cabling, fluid lines, propulsion system and avionics boxes. Heat shield samples already have been removed and sent to a laboratory where their thickness, strength and charring will be examined.
The information will be used to make improvements to Orion’s design before its next flight, Exploration Mission-1, when it will launch uncrewed on top of NASA’s new Space Launch System for the first time into a large orbit around the moon.
While the information is being gathered from the flight test, testing also will continue on Earth. On Dec. 18, engineers dropped a test version of the Orion capsule from a C-17 aircraft 25,000 feet above U.S. Army’s Yuma Proving Ground in Arizona. The latest in a series of tests designed to certify Orion’s parachute system, the test simulated a failure of one of Orion’s three main parachutes for a first-time demonstration of several modifications made to the parachute system to improve its performance.
Panels for the pressure vessel that will form the inner structure for the next Orion crew module are in production and set to be welded together at the end of summer 2015. Meanwhile, the European Space Agency is building the test article of the Orion service module they will be supplying for Exploration Mission-1, and assembly of the launch abort system for that flight will begin in April.
NASA’s Ground Systems Development and Operations Program managed Orion’s cross-country trip from Naval Base San Diego to Kennedy. The crew module will be refurbished for use in Ascent Abort-2 in 2018, a test of Orion’s launch abort system.
