For those of you that weren’t tracking it asteroid 2005 YU55 passed ~325,000 km from Earth on Nov. 9th at 6:30 p.m (ET). Although this may not seem “close” it is by astronomical standards.This was the closest fly-by of an asteroid since 1976.

Purdue University Professor Jay Melosh said the impact of such an object [YU55 is 400 m wide] would carve a crater  ~7 km across and 500 m deep whereas oceanic impact results in a 20 m tsunami [tsunami caused by earthquake that hit Japan earlier this year was estimated at ~10 m high waves].

NASA’s Near-Earth Object (NEO) program tracks ~1000 asteroids that are at least 1 km wide. An impact from one of these NEO’s would cause catastrophic effects. The next fly-by of YU55 is expected in 2028 at a much closer distance…