A newly discovered house-sized asteroid will miss the Earth by less than 17,700 km (11,000 miles) on Monday June 27, 2011. That’s about 23 times closer than the Moon. The size and location of the asteroid, named 2011 MD, should allow observers in certain locations to take a look at the space rock, even with small telescopes. It’s closest approach will be at 13:26 UTC on June 27.
http://www.physorg.com/news/2011-06-asteroid-earth-june.html