In a weeks time, we're having a close encounter:-

http://news.sky.com/story/1048633/asteroid-to-pass-earth-in-record-near-miss

I wonder how old that bit of space junk is? I wonder if it was part of the formation of our Solar System, is it bit chipped off a collision between early coalescing "bodies" in the system or is it a bit of much older space junk captured by the gravitational effect of our solar/planetary system?

All interesting stuff eh?