Update October 10, 2008
Click here to see the latest observations of this meteor. The original story, posted on October 6, 2008, continues below.
Many telescopes around the world are dedicated to scanning the sky, looking for asteroids that might potentially hit Earth. Many candidates have been found, and some have received widespread coverage in the mainstream press. But when the trajectories have been computed, all of them have turned out to be false alarms — until now!
Last night (Sunday, October 5th), a telescope on Mount Lemmon, Arizona, detected a tiny moving blip, the signature of a small chunk of rock moving rapidly through space. Twenty-five observations have been done since then by professional and amateur astronomers around the world, and the object's orbit has been pinned down with fairly high precision. It is almost certain to hit Earth's atmosphere around 10:46 p.m. EDT tonight, October 6th. (That's 2:46 a.m. October 7th, Greenwich Mean Time.)
The rock is roughly 10 feet (3 meters) across, and it's expected to enter the atmosphere above northern Sudan at about 8 miles (12 km) per second. The energy released should be approximately equal to one kiloton of conventional explosives. Fortunately, no damage is expected, since the blast will take place in the upper atmosphere. Some fragments may fall to the ground, but the area is sparsely inhabited and they're unlikely to hit anyone.
The sight and sound, however, should be amazing — especially since the sky will still be dark when this meteor hits. The fireball may be visible over much of northern Africa, the Middle East, and possibly even southern Europe.
Technical details are available in the Minor Planet Electronic Circular.