Spectacularly preserved viscous flow on the NE rim of Byrgius A (19 km diameter) crater. This flow has a form similar to lava flows on the Earth - however it formed as a result of an asteroid or comet slamming into the Moon at hyper-velocity (>16 km/second). So much energy was released in the impact that solid rock was melted and thrown out of the crater where it flowed down the crater flanks (M102573276L, image width 810 m) State University.