The 30 - 66 metre wide asteroid 2013 SB20 will make a close pass (58.0 lunar distances, 0.1491 AU), travelling at 4.53 km/second, to the Earth-Moon system on the 29th September, 2013 @ 20:57 UT ±07:06.
See moreThe Lunar Distance (LD), the distance between Earth and the Moon, equals 384,401 km, (or 0.00256 AU).