Newly discovered small asteroid just misses Earth; next up is much bigger 12/12/12 asteroid

With a diameter of just 72-160 feet, XE54 is a far cry from the over six-mile wide asteroid that wiped out dinosaurs (and about 50% of all life's species) 65 million years ago. But, while it's possible an asteroid of this size would produce nothing more than a brilliant fireball as it disintegrated after entering the atmosphere, a direct hit by remaining rock chunks on a populated region could be disastrous.

via megalextoria.com