Asteroid 2012 KP 24, a smallish rock about 25 meters (80 feet) across, will pass pretty close to the Earth on May 28, buzzing us at a distance of about 30,000 kilometers (18,000 miles) 51,000 kilometers (32,000 miles) [Note: the numbers at JPL have updated, making the pass a bit farther out than the numbers I originally used]. That's close as passes go, but still a clean miss. Closest approach is at about 15:00 UTC (11:00 a.m. Eastern US time) on May 28. It'll actually pass Earth closer than our geosynchronous satellites! At closest approach, it'll whiz by at about 13 km/sec (30,000 mph). I'll note I calculated most of these numbers based on the JPL site linked above, and they may be refined over the next day or two [see?]. It was discovered by the Catalina Sky Survey (as so many near-Earth asteroids are) on the evening of May 23/24. Let me stress, as always, that there is essentially zero chance of impact here. A miss like this is still miss, so don't fret over what will no doubt be a slew of panicky doomsday sites and videos that will pop up about this rock -- that happens every single time we get a near-Earth pass of an asteroid, and yet we're still here! If we see one really and truly on its way to an impact, trust me, I'll let you know. And actually, things like this make me feel safer: we're looking and finding these asteroids! The fact is there are a lot of eyes on the skies right now, scanning the heavens and looking for potential impactors. And note that the JPL page for this rock has all the relevant info there.
Related Posts: - A brief bit about asteroid 2012 DA14 - No, asteroid 2012 DA14 will not hit us next year - Asteroid 2011 AG5: a football-stadium-sized rock to watch carefully - Updated movie of asteroid YU55, plus bonus SCIENCE - Asteroid 2007 TU24: No Danger to Earth