Hayabusa2 is now less than 1000 kilometers away from Ryugu, and the tiny asteroid is beginning to betray its shape. There are enough pixels across it now in Hayabusa2's telescopic optical navigation camera to see that it's definitely not perfectly round. It seems more faceted, with an equatorial bulge, which is a commonly predicted shape for rubble-pile asteroids. There are even hints of surface features, in that the variation in pixel value across the disk doesn't appear perfectly uniform. It's getting exciting! We're about to turn another world from a point of light into a WORLD! More information, including a long exposure shot, are on the Hayabusa2 website.
Ground observation team: JAXA, Kyoto University, Japan Spaceguard Association, Seoul National University. ONC Team: JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu and AIST.
Ryugu from Hayabusa2, 13 June 2018
Image of Ryugu taken with Hayabusa2's ONC-T from a distance of 920 kilometers on June 13, 2018 at around 4:50 UT. The field of view is 6.3 degrees x 6.3 degrees and the exposure time is about 0.09 seconds.