Infrared Telescope to Detect Dim, Dusty Objects

LOS ANGELES (Reuters) - NASA plans next month to launch a space telescope that will scan the heavens for the infrared glow of celestial objects never seen because they are too dim, dusty or distant, scientists said on Tuesday.

The Wide-field Infrared Survey Explorer, or WISE, is expected to reveal hundreds of thousands of dark asteroids lurking undetected in the solar system, and millions of elusive stars and galaxies farther out in space.

The spacecraft, to be carried into orbit by a Delta 2 rocket, will roll out to its launch pad at Vandenberg Air Force Base in California on Friday for a liftoff slated for as early as December 9, managers of the $320 million project said at a news briefing in Washington, D.C.

Its six-month mission is to survey the entire sky for infrared radiation, a form of light invisible to the human eye but emitted from the coldest of objects, including those overlooked by telescopes sensitive only to visible light.

"We expect certainly to see many asteroids, stars and galaxies," said Edward Wright of the University of California, Los Angeles, the mission's principal investigator. "But really I'll be surprised if I'm not surprised ... because we're going to find things that nobody has imagined yet."

The telescope sits in a tank filled with frozen hydrogen that chills it to just slightly above absolute zero, the coldest temperature theoretically attainable, thus preventing the instrument from picking up its own infrared heat.

Among the phenomena WISE is likely to uncover is a large number of failed stars called brown dwarfs -- balls of gas many times smaller than the sun that lack sufficient mass to trigger their own internal stellar engines. Optically invisible, they glow in the infrared spectrum.

Brown dwarfs are believed to be more numerous than actual stars in the nearby universe, and some may reside even closer to Earth than the nearest known star, Proxima Centauri, about 4 light years away, said Peter Eisenhardt, chief project scientist at NASA's Jet Propulsion Laboratory. Both theories are likely to be confirmed by WISE.