Asteroid Steins as seen from the Rosetta spacecraft during the 5 September 2008 flyby. The left column corresponds to 10 min before closest approach, while the right column corresponds to closest approach. The top panel displays images acquired by the OSIRIS camera in the visible. The other two panels display temperature maps: the middle panel corresponds to the case I = 0 J K^-1 m^-2 s^−1/2 and η = 1.05, and the bottom panel to I = 100 J K^-1 m^-2 s^−1/2 and η = 0.79.