Update 2/15/13: To see a meteor passing overhead, check out next week's edition of 'Just for fun'.
Today, a 50-meter across asteroid dubbed 2012 DA14 is not going to hit us. It will, however, come pretty darn close, as you can see from the graphic below.
Image credit: NASA/JPL
At closest approach, occurring at 19:26 UTC (the updated time standard roughly synonymous with Greenwich Mean Time), the asteroid will be about 17,000 miles from the surface of the Earth. As you can see, that’s way inside the moon’s orbit, and even within the orbit of satellites. Unfortunately, it’ll be too dim to see with the naked eye.
Here’s more about it from the folks at NASA.