http://www.space.com/scienceastronomy/mystery_monday_040503.html

A minor rumor has hatched on the Internet that a large and deadly asteroid will strike Earth this fall. Bulletin board discussions cite a 63 percent chance of impact, while concerned readers have e-mailed SPACE.com wondering if it is true.

Astronomers know of no such impending doom.

The rumors are likely rooted in a real event, however. On Sept. 29, 2004 an asteroid the size of a small city will make the closest known pass of such a very large space rock anytime this century.