Binary asteroid glides by Earth

Large asteroid 2008 BT18 is gliding past Earth this weekend and astronomers have just discovered that it is a binary system.

Radar images of the close-approaching space rock reveal two components, a 600 meter primary and a 200+ meter secondary.

Experienced amateur astronomers in the southern hemisphere may be able to photograph the double-rock using backyard telescopes and CCD cameras on July 14th when 2008 BT18 makes its closest approach to Earth
(2 million km).

The asteroid will flit through Canis Major, heading south, glowing like a 13th magnitude star.

Visit http://spaceweather.com for radar images and ephemerides.