锡卡点

2022年8月31日 Siccar Point on Mars Image Credit: NASA/JPL-Caltech/MSSS; Processing & License: Kevin M. Gill Explanation: What created this unusual hill on Mars? No one is sure. A good outlook to survey the surrounding area, Siccar Point stands out from its surroundings in Gale Crater. The unusual mound was visited by the robotic Curiosity rover exploring Mars late last year. Siccar Point not only has a distinctive shape, it has dark rocks above lighter rocks. The apparent much younger age of the dark rocks indicates a time-break in the usual geological ordering of rock layers — by a process yet unknown. The Martian hill is named for Siccar Point on Earth, a place in Scotland itself distinctive as a junction between two different rock layers. Curiosity…