Orbital elements:
2011 YW15 Earth MOID = 0.0137 AU
Epoch 2012 Mar. 14.0 TT = JDT 2456000.5 MPC
M 47.25236 (2000.0) P Q
n 0.54562903 Peri. 353.63981 +0.08156111 -0.99276627
a 1.4832160 Node 91.65711 +0.91826553 +0.04048294
e 0.3285857 Incl. 5.05686 +0.38747413 +0.11303214
P 1.81 H 24.6 G 0.15 U 5
The 31 - 70 metre wide asteroid 2011 YW15 made a close pass (5.1 lunar distances, 0.0131 AU), travelling at 5.09 km/second, to the Earth-Moon system on the 22nd December, 2011 @ 20:26 UT ±00:01.