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Courtesy of Jet Propulsion
Laboratory
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Astrophysicist to probe skies and galaxies
BY AJAY SINGH
ucla today STAFF
Reach for the moon? A UCLA scientist plans to do much more than
that. Edward Wright, professor of physics and astronomy, will be
the principal investigator of a new NASA mission to explore the
entire sky with unprecedented sensitivity, surveying “cool
stars,” faraway galaxies and planetary construction zones.
The mission, known as the Wide-field Infrared Survey Explorer
(WISE), will employ a new space-based telescope equipped with detectors
up to 500,000 times more sensitive than those on any previous project.
NASA recently approved the preliminary design phase of the $208-million
WISE mission, part of NASA’s Medium-class Explorer program,
which is characterized by relatively low-cost, highly focused and
rapidly developed spacecraft. WISE is scheduled to be launched from
Vandenberg Air Force Base in 2008.
During the first six months of its reconnaissance, the telescope
will scan the sky in a section of the electromagnetic spectrum known
as the mid-infrared, which has not yet been widely surveyed. It
consists of electromagnetic waves that are redder, and therefore
longer, than the longest wavelengths the human eye is capable of
seeing.
Within our solar system, WISE will measure the diameter of asteroids,
which absorb sunlight, heat up and glow in the mid-infrared. In
addition, it will track hundreds of cool, or failed, stars, also
known as brown dwarfs, which might be closer to Earth than any known
stars.
“Approximately two-thirds of nearby stars are too cool to
be detected with visible light,” and WISE “will see
most of them,” said Wright, who first proposed the mission
to NASA in 1998. Beyond our solar system, the mission will provide
a comprehensive inventory of young as well as thousands of old stars
and the dusty planet-forming discs surrounding them. WISE will also
monitor the debris trails of comets; the infrared light absorbed
and reemitted by dust, called Zodiacal light; and colliding galaxies
that produce more light, especially infrared light, than any of
the known galaxies in our vast universe.
The telescope on WISE will be operational for only 13 months because,
explained Wright, its detectors must be kept colder than -400 degrees
Fahrenheit, and the frozen hydrogen used to keep them cool will
evaporate with time. But the satellite will remain in space long
after the telescope ceases to function.
The telescope will capture more than a million images that will
help catalog hundreds of millions of space objects — a treasury
of knowledge that will deepen our understanding of the solar system,
the Milky Way and many features of our largely unfathomable universe.
The catalog will specifically help identify targets to be investigated
by NASA’s James Web Space Telescope, slated to be launched
at the beginning of the next decade.
Wright, whose office wall displays a print of van Gogh’s
“Starry Night,” plans to build a team of scientists
at UCLA that will include one of his department colleagues, Ian
McLean, an investigator with the WISE mission. Other scientists
and research facilities across the country will be part of the project.
“WISE is really one small part of what NASA is doing, but
I think it’s great,” Wright said of the Oct. 7 announcement
that the mission is finally a “go.”
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