Keep your helmets on! 2005 YU55 near pass.

Tomorrow (tuesday the 8th of November) an asteroid the size of an aircraft carrier will pass us really close by. It's called 2005 YU55, and while astronomically we can call this a close miss, it will be 0.00217 AU (Eart-Sun distance) away, around 325,000 km or 200,000 mi. This is 15% closer than the distance at which the moon orbits (0.85 lunar distances).

Unfortunately, it will not be visible to the naked eye as it is not big enough, and since it is not a comet, it will not leave a visible trail. The object is approaching from the direction of the Sun, so it will be a daylight object, observable for astronomers who will surely be delighted pointing their optical and infra-red telescopes at it.
It poses no threat of collision, and by calculations, it won't do so for at least 100 years.

The next tracked object to come close to earth (0.6 lunar distances) won't come until 2028. Keep your helmets in good condition for that one as well.

Check out the original story at NASA's site