The 18 - 41 metre wide asteroid 2007 RO17 will make a close pass (42.6 LD, 0.1096 AU) travelling at 8.68 km/second, to the Earth-Moon system on the 12th August 2015 @ 19:02 UT ±12:13.
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The Lunar Distance (LD), the distance between Earth and the Moon, equals 384,401 km, (or 0.00256 AU).