The 31 - 70 metre wide asteroid 2015 HB177 will make a close pass (12.4 LD, 0.0319 AU) travelling at 11.72 km/second, to the Earth-Moon system on the 14th May 2015 @ 15:16 UT ±00:01.
See more
The Lunar Distance (LD), the distance between Earth and the Moon, equals 384,401 km, (or 0.00256 AU).