On December 12, the three-mile-long (4.8 km) asteroid Toutatis came within 4.3 million miles (6.9 million km) of Earth — which is about 18 lunar distances. During the flyby, NASA used its 230-foot-wide (70-meter) Deep Space Network antenna at Goldstone, California, to generate a series of radar data images — which has revealed a slowly spinning and oddly shaped asteroid in fairly spooky detail.
The resolution of the image is at 12 feet (3.75 meters) per pixel, and the video is only 64 frames in length — but it shows an asteroid that's elongated and irregularly shaped. Ridges can be clearly seen, and possibly some craters. The astronomers also noticed some bright glints — what might be surface boulders.
The video also shows that Toutatis is spinning quite slowly. It rotates along its long axis every 5.4 days, and the orientation of its rotational axis (precession) changes every 7.4 days; NASA describes it as a wobbly football that has been thrown very poorly.
And as for Toutatis posing a threat to Earth, it's not. The asteroid won't visit us again until 2069 when it will come within 7.7 lunar distances (1.8 million miles or 3 million km). Models indicate that there is a zero chance that it will hit the Earth within the next four centuries — which is the longest interval that estimates can be made.
Image: NASA/JPL-Caltech.