A giant 1.7-mile wide space rock sailed passed Earth on Friday. The planet was in little danger, however, as Asteroid 1998 QE2 did not come closer than 3.6 million miles (about 15 times the distance to the moon). Still, the flyby captured the attention of the world as it could be viewed through backyard telescopes. Radar images taken this week revealed that the asteroid has its own 2,000-ft diameter moon, big enough to obliterate an area the size of Virginia if it hit. More at Cosmic Log.