* Astronomy

The 81 - 180 metre wide asteroid 2004 YA5 will make a close pass (23.2 lunar distances, 0.0597 AU), travelling at 20.23 km/second, to the Earth-Moon system on the 17th December, 2012 @ 13:10 UT ±07:33. 

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The Lunar Distance (LD), the distance between Earth and the Moon, equals 384,401 km, (or 0.00256 AU).