1998 QE2

Asteroid 1998 QE2, a rock 1.7 miles across, will pass within 3.6 million miles of Earth tomorrow.  NASA says there's no chance of a collision tomorrow, or for the next two centuries.

That's good to know.  A body that size would cause horrendous damage if it slammed into Earth, perhaps throwing back civilization by centuries.  This event is another reminder, therefore, of the need to pursue planetary defense.