I've been investigating some of the recent excitement about dangers from the skies, and particularly asteroid 2007 TU24, which will pass harmlessly by Earth tonight, considerably farther from Earth than the Moon. Here's some recent radar images of the near-Earth object, which is roughly 250 meters in diameter.
Astronomers are more excited about TU24's size than its miss distance. It'll pass by at about 1.4 lunar distances, which is really pretty far away (the Moon is about 30 earth diameters away, so the asteroid will miss us by a distance that is 40 or 50 times our diameter -- that's pretty far). This image from MESSENGER's Earth flyby illustrates that separation: 1.4 lunar distances is not even close.