Asteroid 2010 WC9 will make a close approach to Earth today (5/15/18) at 3:04 p.m. PDT (6:04 p.m. EDT, 22:04 UTC). At the time of closest approach, the asteroid will be no closer to Earth’s surface than about 120,000 miles (200,000 kilometers), which is about half the distance between Earth and the Moon. 2010 WC9 is about 200 to 400 feet (50 to 120 meters) across. The asteroid's velocity at the time of closest approach will be about 29,000 mph (8 miles per second, 12.8 kilometers per second). This flyby is the closest approach 2010 WC9 will make to Earth for at least two centuries.
Asteroid 2010 WC9 was discovered on Nov. 30, 2010, by the
NASA-sponsored Catalina Sky Survey near Tucson, Arizona, and was tracked
for about 10 days before it faded from view. Orbit calculations in 2010
ruled out any chance that the asteroid could pose a threat to our
planet in 2018, but the distance of this year's close approach could not
be predicted precisely until the asteroid was detected again last week
as it approached our planet once again.