The 390 - 880 metre wide asteroid 2004 XK50 will make a close pass (52.4 lunar distances, 0.1346 AU), travelling at 26.38 km/second, to the Earth-Moon system on the 29th December, 2011 @ 10:09 UT ±00:01.
Orbital elements: 2004 XK50 PHA, Earth MOID = 0.0426 AU Epoch 2010 July 23.0 TT = JDT 2455400.5 MPC M 36.94751 (2000.0) P Q n 0.56392731 Peri. 103.88807 -0.74294231 +0.26030636 a 1.4509551 Node 94.26510 -0.51045218 -0.81628226 e 0.6889413 Incl. 38.19784 +0.43298418 -0.51567807 P 1.75 H 19.1 G 0.15 U 2