Radar Observation Gives Insight to Asteroid

Radar imaging at NASA's Goldstone Solar System Radar in the California desert on Dec. 11 and 12, 2010, revealed defining characteristics of recently discovered asteroid 2010 JL33. The images have been made into a short movie that shows the celestial object's rotation and shape. A team led by Marina Brozovic, a scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., made the discovery.

"Asteroid 2010 JL33 was discovered on May 6 by the Mount Lemmon Survey in Arizona, but prior to the radar observations, little was known about it," said Lance Benner, a scientist at JPL. "By using the Goldstone Solar System Radar, we can obtain detailed images that reveal the asteroid's size, shape and rotational rate, improve its orbit, and even make out specific surface features."

Data from the radar reveal 2010 JL33 to be an irregular, elongated object roughly 1.8 kilometers (1.1 miles) wide that rotates once every nine hours. The asteroid's most conspicuous feature is a large concavity that may be an impact crater. The images in the movie span about 90 percent of one rotation.

At the time it was imaged, the asteroid was about 22 times the distance between Earth and the moon (8.5 million kilometers, or 5.3 million miles). At that distance, the radio signals from the Goldstone radar dish used to make the images took 56 seconds to make the roundtrip from Earth to the asteroid and back to Earth again.