The 74 - 160 metre wide asteroid 2008 CO will make a close pass (71.9 lunar distances, 0.1847 AU), travelling at 4.10 km/second, to the Earth-Moon system on the 11th September, 2012 @ 02:20 UT ±1 day 02:34.
See more
The Lunar Distance (LD), the distance between Earth and the Moon, equals 384,401 km, (or 0.00256 AU).