The 26 - 59 metre wide asteroid 2013 RA6 will make a close pass (37.5 lunar distances, 0.0963 AU), travelling at 7.20 km/second, to the Earth-Moon system on the 14th September, 2013 @ 22:59 UT ±00:06.
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The Lunar Distance (LD), the distance between Earth and the Moon, equals 384,401 km, (or 0.00256 AU).