The 51 - 110 metre wide asteroid 2013 RM21 will make a close pass (44.8 lunar distances, 0.1150 AU), travelling at 13.99 km/second, to the Earth-Moon system on the 14th September, 2013 @ 13:49 UT ±00:02.
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The Lunar Distance (LD), the distance between Earth and the Moon, equals 384,401 km, (or 0.00256 AU).
