Central Peak/Mare Boundary The central peak of Tsiolkovskiy crater is surrounded with mare basalt. This NAC frame shows where boulders rolled down the central peak and onto the mare basalt (note the boulder trails). The central peaks of larger lunar craters like Tsiolkovskiy are of particular scientific interest, because they expose rocks uplifted from great depth during the impact process. This image is 890 m wide with an incidence angle of 88° [NASA/GSFC/Arizona State University]. Browse the full NAC image!Related posts: Fractures in the mare of Tsiolkovskiy CraterHummocks and blocks and craters Uplift, Boulders of Tsiolkovskiy Floor of Tsiolkovskiy - Constellation Region of Interest Posted by Sarah Braden on August 25, 2010 09:00 UTC. Mare Back to Images