NASA's WISE eyes skies
Wraps first complete heavenly survey
NASA's Wide-field Infrared Survey Explorer (WISE) has completed its first survey of the entire sky, having spent six months snapping over one million images of the heavens.
Edward Wright, the principal mission investigator at the University of California, enthused: "Like a globe-trotting shutterbug, WISE has completed a world tour with 1.3 million slides covering the whole sky."
To celebrate the event, NASA has released a fine picture of the Pleiades star cluster - actually a photo mosaic made up of "a few hundred image frames":
The agency explains: "Color is representational: blue and cyan represent infrared light at wavelengths of 3.4 and 4.6 microns, which is dominated by light from stars. Green and red represent light at 12 and 22 microns, which is mostly light from warm dust."
Operating at an altitude of 525km, WISE passes over the poles 15 times a day taking a picture every 11 seconds through its 40-cm (16-inch) telescope. To date, it has captured over 100,000 asteroids, including more than 90 new near-Earth objects.
It's also peered at distant luminous galaxies and brown dwarfs, and will continue its mission until around October this year, when the hydrogen keeping its instruments nicely chilled finally evaporates away.
Yes, but as any good conspiracy theorist can tell you, that picture isn't actually the *real* Pleiades, that's the laser-projected computer graphics NASA beams into space to cover what's actually in that part of the sky!
@Misunderstanding of chilled
Kind of my point, like Alaskans using fridges to stop their food freezing etc.
Though I do take on all the other comments - thank you all 8-)
Not just for radiating heat
CCD scanning devices generate picture noise during the long exposures. So if you can keep it cold you generate less noise on the final image.
Amateur astronomers have been using dry ice for decades to achieve the same thing.