At 6:28 p.m. Eastern Standard Time, Asteroid 2005 YU55 (image by JPL / Caltech above), 1,300 feet across and traveling 8 miles per second, passed slightly closer to the Earth than the Moon’s orbit. It has passed safely before and scientists have calculated at least a couple of centuries out that, even with the slight changes that can occur in the orbits of such objects, this particular space rock won’t add to the planet’s pockmarks. The Jet Propulsion Laboratory’s Asteroid and Comet Watch page has much more detail.