Herschel Finds Oceans of Water in Disk of Nearby Star

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 PHONE 818-354-5011
http://www.jpl.nasa.gov

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

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

News release: 2011-327 Oct. 20, 2011

Herschel Finds Oceans of Water in Disk of Nearby Star

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-327&cid=release_2011-327

PASADENA, Calif. -- 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.

"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

-end-

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=oiJTKZOBIeLVJfJ&s=mwK6JdOVJiISKcN1KwG&m=jvJ3IjPUJdLTKlK

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=rvLZL8MNLhK2LpI&s=mwK6JdOVJiISKcN1KwG&m=jvJ3IjPUJdLTKlK