The 120 - 280 metre wide asteroid 2014 QO33 made a close pass (55.3 lunar distances, 0.1421 AU), travelling at 5.49 km/second, to the Earth-Moon system on the 11th September 2014 @ 01:01 UT ±00:12.
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The Lunar Distance (LD), the distance between Earth and the Moon, equals 384,401 km, (or 0.00256 AU).