May 30, 2013: Approaching asteroid 1998 QE2 has a moon. Researchers found it in a sequence of radar images obtained by the 70-meter Deep Space Network antenna at Goldstone, Calif., on the evening of May 29th (May 30th Universal Time) when the asteroid was about 6 million kilometers from Earth.

The preliminary estimate for the size of the asteroid's satellite is approximately 600 meters wide. The asteroid itself is approximately 2.7 kilometers in diameter and has a rotation period of less than four hours.

First radar images of asteroid 1998 QE2 were obtained when the asteroid was about 3.75 million miles (6 million kilometers) from Earth. The radar collage covers a little bit more than two hours.  Image credit: NASA/JPL-Caltech/GSSR

The radar observations were led by scientist Marina Brozovic of NASA's Jet Propulsion Laboratory in Pasadena, CA.

These findings show that 1998 QE2 is a binary asteroid. In the near-Earth population, about 16 percent of asteroids that are about 200 meters or larger are binary or triple systems  Also revealed in the radar imagery of 1998 QE2 are several dark surface features that suggest large concavities.

The closest approach of the asteroid occurs on May 31 at 1:59 p.m. Pacific (4:59 p.m. Eastern / 20:59 UTC), when the asteroid will get no closer than about 5.8 million kilometers, or about 15 times the distance between Earth and the Moon. This is the closest approach the asteroid will make to Earth for at least the next two centuries. Asteroid 1998 QE2 was discovered on Aug. 19, 1998, by the Massachusetts Institute of Technology Lincoln Near Earth Asteroid Research (LINEAR) program near Socorro, N.M.

The resolution of these initial images of 1998 QE2 is approximately 75 meters per pixel. Resolution is expected to increase in the coming days as more data become available. Between May 30 and June 9, radar astronomers using the Deep Space Network antenna at Goldstone, Calif., and the Arecibo Observatory in Puerto Rico, will perform an extensive campaign of observations on asteroid 1998 QE2. The two telescopes have complementary imaging capabilities that will enable astronomers to learn as much as possible about the asteroid during its brief visit near Earth.

Stay tuned for updates.

Credits:

Author: Dr. Tony Phillips |  Production editor: Dr. Tony Phillips | Credit: Science@NASA

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NASA places a high priority on tracking asteroids and protecting our home planet from them. In fact, the United States has the most robust and productive survey and detection program for discovering near-Earth objects. To date, U.S. assets have discovered more than 98 percent of the known Near-Earth Objects.

In 2012, the Near-Earth Object budget was increased from $6 million to $20 million. Literally dozens of people are involved with some aspect of near-Earth object research across NASA and its centers. Moreover, there are many more people involved in researching and understanding the nature of asteroids and comets, including those objects that come close to Earth, plus those who are trying to find and track them in the first place.

In addition to the resources NASA puts into understanding asteroids, it also partners with other U.S. government agencies, university-based astronomers, and space science institutes across the country that are working to track and better understand these objects, often with grants, interagency transfers and other contracts from NASA.

NASA's Near-Earth Object Program at NASA Headquarters, Washington, manages and funds the search, study, and monitoring of asteroids and comets whose orbits periodically bring them close to Earth. JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena.