by Jonathan Skillings
WISE view of constellation Carina
This very first image from the WISE space telescope shows 3,000 stars,
more or less, in the constellation Carina.
(Credit: NASA/JPL-Caltech/UCLA )
Just about everybody gets excited about the first picture from a new
camera, and NASA is no exception to the rule.
In this case, the "first light" image came from the Wide-field
Infrared Survey Explorer, aka WISE, which NASA sent into space last
month. Just last week, the agency popped off the space telescope's
"lens cap," a cover that shielded the optical gear from the travails
of lift-off and from the spacecraft's own heat.
WISE does like things chilly, says NASA--really, really chilly:
To sense the infrared glow of stars and galaxies, the WISE
spacecraft cannot give off any detectable infrared light of its own.
This is accomplished by chilling the telescope and detectors to
ultra-cold temperatures. The coldest of WISE's detectors will operate
at less than 8 Kelvin, or minus 445 degrees Fahrenheit.
Brr. But the images that come from the 9-foot-tall, 1,400-pound WISE
spacecraft will no doubt warm the hearts of NASA's mission planners
and legions of astronomers as the telescope scans the firmament for
hidden objects, ranging from asteroids to galaxies. In orbit around
Earth, WISE will take motion-corrected infrared images every 11
seconds, a rate that the space agency says will result in millions of
images of the sky.
NASA trains WISE eye on the sky (photos)
On Wednesday, NASA released the very first image, taken shortly after
the cover was jettisoned and WISE got its initial glimpse of the
heavens--in this case, staring at a fixed portion of the sky as NASA
engineers calibrated the spacecraft's pointing system. The image shows
a section of the constellation Carina, near the Milky Way, that
includes some 3,000 stars, give or take a few. It's a patch of the sky
about three times bigger than a full moon, NASA says.
The 8-second exposure shows infrared light from three of WISE's four
wavelength bands--blue, green and red, which, according to NASA,
correspond to 3.4, 4.6, and 12 microns, respectively.
Over time, data from WISE will be used in the creation of navigation
charts for other missions, including those of the Hubble and Spitzer
space telescopes. Alas, WISE's moment of glory won't last long--the
frozen hydrogen that keeps the instruments at those necessary
ultra-cold temperatures is expected to evaporate by about October.
The first survey of the sky by WISE will take about six months,
followed by a second scan, of just half the sky, over three months.
NASA will be releasing selected images to the public starting in
February. It expects to release preliminary survey images in April
2011, and to have a final atlas and catalog ready by March 2012.
And those images should be dandies. WISE has a resolution of 4 million
pixels, spread about equally over the system's four detectors. The
last time an infrared survey of the sky took place, in 1983, the
Infrared Astronomical Satellite (IRAS) taking the pictures could
muster only 62 pixels, period.