This collage of radar images of near-Earth asteroid 2005 WK4 was collected by NASA scientists using the 230-foot (70-meter) Deep Space Network antenna at Goldstone, California, on August 8, 2013. The asteroid is between 660 and 980 feet (200 and 300 meters) in diameter; it has a rounded and slightly asymmetric shape. As it rotates a number of features are evident that suggest the presence of some flat regions and a bulge near the equator. The data were obtained between 12:40 and 7:10 a.m. PDT (3:40 and 10:10 a.m. EDT). At the time of the observations, the asteroid's distance was about 1.93 million miles (3.1 million kilometers), which is 8.2 lunar distances away. The data were obtained over an interval of 6.5 hours as the asteroid completed about 2.4 rotations. The resolution is 12 feet (3.75 meters) per pixel.
Image credit: NASA/JPL-Caltech/GSSR
Note: For more information, see Radar Images of Asteroid 2005 WK4.