The 71 - 160 metre wide asteroid 2015 RO36 made a close pass (21.1 LD, 0.0542 AU) travelling at 15.85 km/second, to the Earth-Moon system on the 8th September 2015 @ 14:35 UT ±00:01.
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The Lunar Distance (LD), the distance between Earth and the Moon, equals 384,401 km, (or 0.00256 AU).