Revived spacecraft spots new asteroid

A NASA spacecraft recently bought out of hibernation has spotted a never-before-seen asteroid.

NEOWISE (Near-Earth Object Wide-field Infrared Survey Explorer) was reactivated in September 2013 and received a new name and new mission: to assist NASA’s efforts to identify potentially hazardous near-Earth objects (NEOs) and characterise previously detected asteroids that could become potential targets for future exploration missions.

Its first discovery was near-Earth asteroid 2013 YP139; it picked out the moving object against a background of stationary stars. As it circled the Earth, it observed the asteroid several times over half a day before the object moved beyond its view.

“We are delighted to get back to finding and characterising asteroids and comets, especially those that come into Earth’s neighbourhood,” said Amy Mainzer, the mission’s principle investigator from the Jet Propulsion Laboratory (JPL). “With our infrared sensors that detect heat we can learn about their sizes and reflectiveness.”

Based on the infrared brightness of 2013 YP139 – which is about 27 million miles from Earth – scientists estimate that it is roughly 0.4 miles in diameter and extremely dark like a piece of coal. Its tilted elliptical orbit could bring it as close as 300,000 miles from the Earth, a little more than the distance to the moon – but not within the next century.

NEOWISE began life as WISE, but was placed into hibernation in 2011 when its primary mission was completed. During this mission it made the most comprehensive survey to date of asteroids and comets, discovering more than 34,000 asteroids and characterising 158,000 throughout the solar system.