You might not expect snapshots of the sky to reveal many new surprises. After all, astronomers have been taking pictures of the universe for a century and a half. Yet the pictures snapped this year by a small satellite have revealed thousands of objects that no one had ever seen before -- from asteroids in our own solar system to galaxies that are billions of light-years away.
The satellite is WISE -- the Wide-field Infrared Survey Explorer. It looks at the sky in the infrared -- wavelengths of light that are invisible to the human eye. Earth's atmosphere blocks most of the infrared, so the best view is from space.
WISE's mission was to survey the entire sky -- a mission it completed in July. Now, it's repeating the survey, looking for new objects or helping pin down the locations of ones it saw the first time.
WISE doesn't study the objects it sees -- it just finds them. Astronomers will follow up on its discoveries with more-detailed observations by other telescopes.
The list of targets includes more than 30,000 new asteroids in the solar system, including more than a hundred whose orbits come close to Earth's orbit. WISE has also discovered faint stars, and the "failed" stars known as brown dwarfs. It's seen nurseries that are giving birth to new stars, and remote galaxies that are giving birth to millions of stars. Astronomers will spend years studying the objects in WISE's huge collection of snapshots.
More about WISE tomorrow.
Script by Damond Benningfield, Copyright 2010