* Astronomy

Orbital elements:
2012 XK55                                                Earth MOID = 0.1618 AU
Epoch 2012 Sept. 30.0 TT = JDT 2456200.5                MPC
M 342.46467              (2000.0)            P               Q
n   0.23477380     Peri.  183.09053     +0.19604229     -0.97616032
a   2.6023735      Node   255.61800     +0.90172862     +0.21678783
e   0.5596487      Incl.    5.51879     +0.38529587     -0.01068031
P   4.20           H   23.9           G   0.15           U   8

MPEC 2012 - X45

The 44 - 97 metre wide asteroid 2012 XK55 will make a close pass (67.6 lunar distances, 0.1738 AU), travelling at 5.75 km/second, to the Earth-Moon system on the 11th December, 2012 @ 18:41 UT ±05:14. 

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