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NASA Invites Twitter Followers to Launch of Earth-Observing Satellite

October 20, 2011 Leave a comment

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.

Full Story: http://www.nasa.gov/home/hqnews/2011/oct/HQ_11-358_NPP_Tweetup.html

Herschel Finds Ocean of Water in Disk of Nearby Star

October 20, 2011 Leave a comment

Image credit: NASA/JPL-Caltech

Image credit: NASA/JPL-Caltech

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 waterlogged 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.

Full Story: http://www.jpl.nasa.gov/news/news.cfm?release=2011-327

How Blue Stragglers Stay So Young

October 20, 2011 Leave a comment

Mysterious “blue stragglers” are old stars that appear younger than they should be: they burn hot and blue. Several theories have attempted to explain why they don’t show their age, but, until now, scientists have lacked the crucial observations with which to test each hypothesis.

Armed with such observational data, two astronomers from Northwestern University and the University of Wisconsin-Madison report that a mechanism known as mass transfer explains the origins of the blue stragglers. Essentially, a blue straggler eats up the mass, or outer envelope, of its giant-star companion. This extra fuel allows the straggler to continue to burn and live longer while the companion star is stripped bare, leaving only its white dwarf core.

The scientists report their evidence in a study to be published Oct. 20 by the journal Nature.

The majority of blue stragglers in their study are in binaries: they have a companion star. “It’s really the companion star that helped us determine where the blue straggler comes from,” said Northwestern astronomer Aaron M. Geller, first author of the study. “The companion stars orbit at periods of about 1,000 days, and we have evidence that the companions are white dwarfs. Both point directly to an origin from mass transfer.”

Full Story: http://www.northwestern.edu/newscenter/stories/2011/10/blue-stragglers.html