The 53 - 120 metre wide asteroid 2017 KU34 will make a close pass (50.1 lunar distances, 0.12876 AU), travelling at 4.28 km/second, to the Earth on the 19th May 2018 @ 05:00 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).