Asteroid Survey Finds Over 33,000 Space Rocks

It's been one helluva ride: For the last year, NASA's Wide-field Infrared Survey Explorer, or WISE, has mapped the entire sky. It's been a prodigious effort, resulting in the imaging of more than 2.7 million images of objects ranging from galaxies to asteroids and comets.

Unfortunately for WISE, it ran out of gas - literally. By early October 2010, the $320 million telescope had spent all of the frozen coolant that keeps its instrumentation cold. But still that didn't bring the mission to an abrupt halt. Two of WISE's four infrared cameras continued to operate, allowing NASA operators back on Earth to continue to hunt for new asteroids and comets for another four months.

Along the way, WISE has sent back breathtaking photos of previously unknown objects. NASA's Tuesday update on this secondary mission, called NEOWISE, involves a survey in which 20 new comets, more than 33,000 asteroids, and 134 other near-Earth objects were revealed. (They are called near-Earth objects because their orbits come 28 million miles of Earth's circumference of the sun.) Scientists are likely to pay especial attention to this latter group because some may eventually present a collision hazard with the Earth.

The WISE spacecraft now enters a hibernation state and remain in polar orbit around Earth until NASA decided to call it back into service.