2012 KT42, an asteroid about the size of a school bus, went by us at a distance of about 9,000 miles - larger than the diameter of the Earth but still a near miss, astronomically speaking.  

Why weren't hysterics worried about this one?   They're still obsessing with Nibiru, I suppose. Plus, small rocks are never known about that far in advance.

Science 2.0 fave Phil Plait, the Bad Astronomer, compiled the scoop on this rock while the rest of us ate hot dogs yesterday and tried to explain the difference between Memorial Day and Veterans Day to all those people who just like a long weekend.
And as usual, I’ll point out that this discovery is a good thing! It shows we can find them, and that’s important. If we ever do discover an asteroid on a collision course that’s big enough to hurt us, the first step is to find it. And we’re getting better at that all the time.
Here's a nifty animation he linked to but there are lots more details over at Bad Astronomy.  H/T/ Eric Berger,  Houston Chronicle