Monday, January 26, 2015, Astronomers took the opportunity to examine a massive asteroid with radar today, as it passed by us at a safe distance, and they were rewarded in a very special way.
When asteroid 2004 BL86 swung by Earth today - with more than enough room to spare, at roughly 3 times the distance to the Moon - astronomers at NASA's Goldstone Deep Space Communications Complex aimed the big 70-metre antenna there at it, bouncing radio waves off the asteroid to get a better idea of its size, shape and rate of rotation, and possibly even its composition. What they didn't count on, though, is discovering that the asteroid has a companion, in the form of a small moon!
