The 11 - 25 metre wide asteroid 2009 HH21 made a close pass (12.6 Lunar Distances, 0.0323 AU), travelling at 4.40 km/s, to the Earth-Moon system on the 26th April 2009. See more
The Lunar Distance (LD), the distance between Earth and the Moon, equals 384,401 km, (or 0.00256 AU).
Orbital elements: 2009 HH21 Earth MOID = 0.0279 AU Epoch 2009 June 18.0 TT = JDT 2455000.5 MPC M 26.29263 (2000.0) P Q n 0.59142555 Peri. 12.01956 -0.70109528 +0.71189169 a 1.4056245 Node 213.49093 -0.66021814 -0.66975111 e 0.2650797 Incl. 4.25427 -0.26940195 -0.21129051 P 1.67 H 26.8 G 0.15 U 8