NEOWISE

The NEOWISE mission uses a space telescope to hunt for asteroids and comets, including those that could pose a threat to Earth. During its planned four-year survey -- from December 2013 through 2017 -- NEOWISE will rapidly identify and characterize near-Earth objects, gathering data on their size and other key measurements.

Launched in December 2009 as the Wide-Field Infrared Survey Explorer, or WISE, the space telescope was originally designed to survey the sky in infrared, detecting asteroids, stars and some of the faintest galaxies in space. It did so successfully until completing its primary mission in February 2011. Observations resumed in December 2013, when the telescope was taken out of hibernation and re-purposed for the NEOWISE project as an instrument to study near-Earth objects, or NEOs, as well as more distant asteroids and comets.

During its primary mission, NEOWISE detected more than 158,000 minor planets, 34,000 of which had never been discovered previously.

NEOWISE data have been used to set limits on the numbers, orbits, sizes, and probable compositions of asteroids throughout our solar system, and enabled the discovery of the first known Earth Trojan asteroid.