[meteorite-list] Herschel Space Observatory Finds Oceans of Water in Planet-Forming Disk Around Nearby Star

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 20 Oct 2011 12:29:27 -0700 (PDT)
Message-ID: <201110201929.p9KJTRg9005343_at_zagami.jpl.nasa.gov>

Oct. 20, 2011

Trent J. Perrotto
Headquarters, Washington
202-358-0321
trent.j.perrotto at nasa.gov

Whitney Clavin
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-4673
whitney.clavin at jpl.nasa.gov

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.

For NASA's Herschel website, visit:

http://www.nasa.gov/herschel

For ESA's Herschel website, visit:

http://www.esa.int/SPECIALS/Herschel/index.html
        
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Received on Thu 20 Oct 2011 03:29:27 PM PDT