* Astronomy

Orbital elements:
2012 XL55                                                Earth MOID = 0.0008 AU
Epoch 2012 Sept. 30.0 TT = JDT 2456200.5                MPC
M 307.77803              (2000.0)            P               Q
n   0.43497938     Peri.   90.13721     -0.97471690     -0.21971168
a   1.7251370      Node    77.17081     +0.18481220     -0.89502352
e   0.6467124      Incl.    2.39035     +0.12558429     -0.38814905
P   2.27           H   27.0           G   0.15           U   8

MPEC 2012 - X46

The 10 - 23 metre wide asteroid 2012 XL55 will make a close pass (4.2 lunar distances, 0.0109 AU), travelling at 18.76 km/second, to the Earth-Moon system on the 11th December, 2012 @ 11:11 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).