Mosaic of range-Doppler radar images of (52768) 1998 OR2 obtained on April 19-20 UT reveal the near-Earth asteroid to be approximately 2 km in diameter (7.5 m/pixel vertically) with a crater-like concavity rotating across the radar-illuminated side (top of image) during roughly 2 hours of radar imaging.
Arecibo Observatory/NASA/NSF
2020-04-19
<a rel="nofollow" class="external free" href="http://www.naic.edu/~pradar/press/1998OR2.php">http://www.naic.edu/~pradar/press/1998OR2.php</a>