By Glynn Wilson –
A reactivated NASA spacecraft designed to identify the population of potentially threatening near-Earth objects has spotted a new asteroid about 27 million miles (43 million kilometers) from Earth.
Based on its infrared brightness, scientists estimate it to be roughly 0.4 miles (650 meters) in diameter and extremely dark, like a piece of coal. The asteroid circles the sun in an elliptical orbit tilted to the plane of our solar system and is classified as “potentially hazardous.”
It is possible for its orbit to bring it as close as 300,000 miles from Earth, a little more than the distance to the moon, although probably not in the next century, according to a statement on the finding issues by NASA on Tuesday.
The 2013 YP139 asteroid was spotted and identified by NASA’s Near-Earth Object Wide-field Infrared Survey Explorer, a.k.a. NEOWISE.
It was originally called the Wide-field Infrared Survey Explorer (WISE), which had made the most comprehensive survey to date of asteroids and comets. The spacecraft was shut down in 2011 after its primary mission was completed.
But in September 2013, it was reactivated, renamed and given a new mission. In addition to identifying potentially hazardous near-Earth objects, the craft also can assist in characterizing previously detected asteroids that could be considered potential targets for future exploration missions.
On its first discovery on its renewed mission, it spotted and identified the asteroid on Dec. 29. The mission’s sophisticated software picked out the moving object against a background of stationary stars. As the craft circled Earth scanning the sky, it observed the asteroid several times over half a day before the object moved beyond its view.
Researchers at the University of Arizona used the Spacewatch telescope at the Kitt Peak National Observatory southwest of Tucson to confirm the discovery. Peter Birtwhistle, an amateur astronomer at the Great Shefford Observatory in West Berkshire, England, also contributed follow-up observations.
The agency expects this find will be the first of hundreds of asteroid discoveries for the revamped craft.
“We are delighted to get back to finding and characterizing asteroids and comets, especially those that come into Earth’s neighborhood,” said Amy Mainzer, the mission’s principal investigator from NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “With our infrared sensors that detect heat, we can learn about their sizes and reflectiveness.”
On its previous mission in 2010 and early 2011, the craft discovered more than 34,000 asteroids and characterized 158,000 throughout the solar system.
Now it will continue to detect asteroids and comets and the observations will be automatically sent to the clearinghouse for solar system bodies, the Minor Planet Center in Cambridge, Mass., for comparison against the known catalog of solar system objects and to determine orbit if the object is not known. A community of professional and amateur astronomers will provide follow-up observations, establishing firm orbits for the previously unseen objects.
Infrared sensors, similar to the cameras on NEOWISE, are a powerful tool for discovering, cataloging and understanding the asteroid population. Some of the objects about which NEOWISE will be collecting data could become candidates for NASA’s announced asteroid initiative, which will be the first mission to identify, capture and relocate an asteroid for astronauts to explore.
“The initiative represents an unprecedented technological feat that will lead to new scientific discoveries and technological capabilities that will help protect our home planet and achieve the goal of sending humans to an asteroid by 2025,” a NASA spokesperson said.
The lab in Pasadena, overseen by Caltech, manages the project for NASA’s Science Mission Directorate in Washington, while the Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace and Technologies Corp. of Boulder, Colo., built the spacecraft and science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena.
More information about NEOWISE is available online here.
© 2014, Glynn Wilson. All rights reserved.