Oct 20 2011
From The Space Library
RELEASE: 11-355 HERSCHEL SPACE OBSERVATORY FINDS OCEANS OF WATER IN PLANET-FORMING DISK AROUND NEARBY STAR
WASHINGTON -- Using data from the Herschel Space Observatory, astronomers have detected for the first time cold water vapor enveloping a dusty disk around a young star. The findings suggest that this disk, which is poised to develop into a solar system, contains great quantities of water, suggesting that water-covered planets like Earth may be common in the universe. Herschel is a European Space Agency mission with important NASA contributions. Scientists previously found warm water vapor in planet-forming disks close to a central star. Evidence for vast quantities of water extending out into the cooler, far reaches of disks where comets take shape had not been seen until now. The more water available in disks for icy comets to form, the greater the chances that large amounts eventually will reach new planets through impacts. "Our observations of this cold vapor indicate enough water exists in the disk to fill thousands of Earth oceans," said astronomer Michiel Hogerheijde of Leiden Observatory in The Netherlands. Hogerheijde is the lead author of a paper describing these findings in the Oct. 21 issue of the journal Science. The star with this water-logged disk, called TW Hydrae, is 10 million years old and located about 175 light-years away from Earth, in the constellation Hydra. The frigid watery haze detected by Hogerheijde and his team is thought to originate from ice-coated grains of dust near the disk's surface. Ultraviolet light from the star causes some water molecules to break free of this ice, creating a thin layer of gas with a light signature detected by Herschel's Heterodyne Instrument for the Far-Infrared, or HIFI. "These are the most sensitive HIFI observations to-date," said Paul Goldsmith, NASA project scientist for the Herschel Space Observatory at the agency's Jet Propulsion Laboratory in Pasadena, Calif. "It is a testament to the instrument-builders that such weak signals can be detected." TW Hydrae is an orange dwarf star, somewhat smaller and cooler than our yellow-white sun. The giant disk of material that encircles the star has a size nearly 200 times the distance between Earth and the sun. Over the next few million years, astronomers believe matter within the disk will collide and grow into planets, asteroids and other cosmic bodies. Dust and ice particles will assemble as comets. As the new solar system evolves, icy comets are likely to deposit much of the water they contain on freshly created worlds through impacts, giving rise to oceans. Astronomers believe TW Hydrae and its icy disk may be representative of many other young star systems, providing new insights on how planets with abundant water could form throughout the universe. Herschel is a European Space Agency cornerstone mission launched in 2009, carrying science instruments provided by consortia of European institutes. NASA's Herschel Project Office based at JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the U.S. astronomical community. Caltech manages JPL for NASA.
RELEASE: 11-357 NASA INVITES TWITTER FOLLOWERS TO LAUNCH OF EARTH-OBSERVING SATELLITE
WASHINGTON -- Twenty lucky followers of NASA's Twitter account will get behind-the-scenes access at the launch of the agency's next Earth-observing satellite mission. They will participate in a daylong Tweetup program at Vandenberg Air Force Base in California on Thursday, Oct. 27 and view the launch of NASA's NPP satellite, which is scheduled to lift off aboard a United Launch Alliance Delta II rocket between 2:48 and 2:57 a.m. PDT on Friday, Oct. 28. The National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) will collect critical data on long-term climate change and short-term weather conditions. With NPP, NASA continues gathering key data records initiated by the agency's Earth Observing System satellites, monitoring changes in the atmosphere, oceans, vegetation, ice and solid Earth. Tweetup participants were selected from more than 625 people who registered online. They will share their experiences with their followers through the social networking site Twitter. Attendees are coming from California, the District of Columbia, Illinois, Kansas, New York and Oregon. Beginning at 9:30 a.m. PDT on Oct. 27, NASA will broadcast a portion of the Tweetup when attendees talk with NASA Astronaut Piers Sellers, the deputy director of the Sciences and Exploration Directorate at NASA's Goddard Space Flight Center in Greenbelt, Md.; NPP Project Scientist Jim Gleason; NPP Systems Manager Janice Smith; NASA Launch Director Tim Dunn; and Scott Asbury, a senior program manager with Ball Aerospace & Technologies, Corp. in Boulder, Colo. Participants also will tour Vandenberg's launch facilities, including a visit to the launch pad. Vandenberg is headquarters for the 30th Space Wing, which manages space and missile testing for the Department of Defense and places satellites into polar orbit from the West Coast using expendable boosters. Launch management for the mission is the responsibility of NASA's Launch Services Program at the Kennedy Space Center in Florida. NASA has invited its Twitter followers to seven previous launches, but this is the first from the West Coast.
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