mountain profile Institute for Astronomy University of Hawaii

UH Astronomers Confirm Discovery of Near-Earth Asteroid

When the Wide-field Infrared Survey Explorer (WISE) spacecraft launched by NASA last month spotted its first near-Earth asteroid on January 12, University of Hawaii astronomers using the UH 2.2-meter (88-inch) telescope on Mauna Kea quickly confirmed the discovery.

“WISE observes only in a very narrow band completely around the sky. While an asteroid lies within that band, WISE can observe it repeatedly, but once the asteroid moves out of the band, it’s the job of ground-based astronomers to follow the new discovery and refine the orbit determination,” explained UH astronomer Dr. David Tholen. Tholen and graduate students Marco Micheli and Garrett Elliott found that the object, designated as 2010 AB78 by the Minor Planet Center, has an orbit that brings it close to Earth’s orbit.

Astronomers have been busy finding and tracking these near-Earth objects, potentially “killer asteroids,” for the last decade. One such discovery, 2008 TC3, actually did impact the Earth over Sudan in October 2008, though the object was small enough that only a few pounds of meteorite fragments made it to the ground, with the rest of the space rock being vaporized during its fiery flight through Earth’s atmosphere. However, there is no danger that 2010 AB78 will hit Earth.

Unlike the ground-based searches, which see asteroids in reflected sunlight, WISE detects asteroids by the heat they radiate. To prevent the heat from the spacecraft itself from overloading the detectors, the telescope is cooled using solid hydrogen. The amount of coolant on-board will allow the spacecraft to operate for about nine months, enough time for WISE to sweep the entire sky within its narrow band. During the satellite’s short lifetime, the WISE science team expects to discover about 100,000 new asteroids, including several hundred near Earth.

Tholen’s work is funded by a grant from the National Science Foundation.


JPL press release