A close-up of the Mercury Laser Altimeter (MLA) profile of Mercury acquired during MESSENGER’s first Mercury flyby on January 14, 2008. Comparison with an Arecibo radar image mosaic (bottom) provided by Harmon and co-workers shows that the two largest depressions are adjacent impact craters. The craters have rim-to-rim diameters of 107 km (left) and 122 km (right). The root mean square roughness of the floor the larger crater is ~35 m. The vertical exaggeration in the figure is 35:1.
Credit: NASA/Goddard Space Flight Center/Cornell University/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington