As asteroid the size of a football field almost hit the Earth last week, passing closer than 1/3 of the distance between the Earth and the Moon. Even more alarming, this near miss was only detected 3 days after the event. According to the article, "This is only the sixth known asteroid to penetrate the Moon's orbit, and by far the biggest." Had it landed, it would have struck "with a force rivaling the largest H-bombs". Personally, I'm glad it didn't land in some politically sensitive place like the India-Pakistan border, where it could have been mistaken for a military attack and triggered even worse events. The BBC has similar coverage. (Via Metafilter.)