The six red dots in this composite picture indicate the location of
the first new near-Earth asteroid seen by NASA’s Near-Earth Object
Wide-field Infrared Survey Explorer (NEOWISE) since the spacecraft came
out of hibernation in December 2013. The asteroid, called 2013 YP139, is
the first of hundreds of space-rock discoveries expected during its
renewed mission. The inset shows a zoomed-in view of one of the
detections of 2013 YP139. Image credit: NASA/JPL-Caltech
2013 YP139 was discovered by NEOWISE on Dec. 29, 2013. The mission’s
sophisticated software picked out the moving object against a background
of stationary stars.
Near-Earth objects are asteroids and comets with orbits that come
close to Earth’s path around the sun. 2013 YP139, is currently about 27
million miles (43 million kilometers) from Earth. Based on its infrared
brightness, scientists estimate it to be approximately 0.4 miles (650
meters) in diameter and extremely dark. Because NEOWISE is an infrared
telescope, it senses heat from asteroids. 2013 YP139 is as dark as a
piece of coal, and it glows brightly at infrared wavelengths. The
shortest infrared wavelength, 3.4 microns, is color-coded blue, and the
longer wavelength, 4.6 microns, is color-coded red. The asteroid
appears as a string of red dots because it is much cooler than the
stars. Stars are thousands of degrees, but the asteroid is close to
room temperature, so it is red in these images.
While asteroid 2013 YP139 orbits the sun in an elliptical orbit
nearly in the plane of our solar system and is classified as a
potentially hazardous asteroid, it is not likely to approach within
Earth’s vicinity anytime over the next 100 years. However, the
asteroid’s future motion can bring it within about 300,000 miles
(490,000 kilometers) of Earth’s orbit, so its long-term motion will be
closely monitored.
The image is about 1.5 degrees across. Asteroid 2013 YP139 was
traveling across the sky at about 3.2 degrees per day when these images
were taken. For reference, the full moon is about 0.5 degree across.
NEOWISE originated as a mission called WISE, which was put into
hibernation in 2011 upon completing its goal of surveying the entire sky
in infrared light. WISE cataloged three quarters of a billion objects,
including asteroids, stars and galaxies. In August 2013, NASA decided to
reinstate the spacecraft on a mission to find and characterize more
asteroids.
JPL manages NEOWISE for NASA’s Science Mission Directorate at the
agency’s headquarters in Washington. The Space Dynamics Laboratory in
Logan, Utah, built the science instrument. Ball Aerospace &
Technologies Corp. of Boulder, Colo., built the spacecraft. Science
operations and data processing take place at the Infrared Processing and
Analysis Center at the California Institute of Technology in Pasadena.
Caltech manages JPL for NASA.
More information is online at http://www.nasa.gov/wise, http://wise.astro.ucla.edu and http://www.jpl.nasa.gov/wise.
Source: NASA
