During the month of December, the Planetary Radar Group at Arecibo Observatory has observed near-Earth asteroid 2003 SD220, which will make its closest approach to Earth on Christmas Eve. Although designated as “potentially hazardous,” this asteroid will be 28 times further away than our Moon and therefore poses no present danger to Earth.
Asteroid 1998 WT24 safely flew past Earth on 11 December at a distance of about 2.6 million miles (11 lunar distances). During its flyby, NASA scientists used the 230-foot (70-metre) DSS-14 antenna at Goldstone, California, to probe it with microwave transmissions. Using this technique, they created the highest-resolution radar pictures of the asteroid — 2.5 times better than when it was last imaged, 14 years ago.