I'm not sure why, but I seem to be on an astronomy kick lately. I came across a little tidbit today that reminded me of Deep Impact and Armageddon. At 13:44 UT today (March 2, 2009), a 30 meter asteroid (identified as 2009 DD45) will pass by earth and miss by only 37,282 miles. Even though it isn't that big, it's big enough that it would do some serious damage if it hit. As an example, the meteor that made the Barringer Crater in Arizona is estimated to be about the same size as this one, and the Barringer crater is 570 feet deep and nearly a mile across. To give you an idea how close we came to another crater, 37,000 miles is not quite twice the distance of a geostationary orbit. Unfortunately, you will not be able to see it because it is too small and moving too fast (1/2 degree per minute). I take comfort that we are least finding these objects. I guess it doesn't matter much either way, since there will not be much to do if one was found to be on a collision course. At least we will know it's coming.
FYI, asteroid 2009 EA4 will pass by earth tomorrow doing 21,050 mph. Its closest distance will be over 1.7 million miles -- still close by astronomical standards.