Orbital elements:
2015 HN1 Earth MOID = 0.0542 AU
Epoch 2015 June 27.0 TT = JDT 2457200.5 MPC
M 42.03706 (2000.0) P Q
n 0.58666639 Peri. 184.41070 -0.90371421 +0.42631648
a 1.4132161 Node 20.96107 -0.38935833 -0.78006647
e 0.2521598 Incl. 6.32841 -0.17804695 -0.45798533
P 1.68 H 27.1 G 0.15 U 7
The 10 - 23 metre wide asteroid 2015 HN1 made a close pass (21.3 LD, 0.0547 AU) travelling at 4.39 km/second, to the Earth-Moon system on the 16th April 2015 @ 14:35 UT ±00:46.