NASA’s Curiosity Mars rover found preserved, ancient mud cracks that scientists believe were formed after long cycles of wet and dry conditions over many years. The discovery marks the first evidence of these wet-dry cycles on Mars. The cracks were found while the rover explored a transitional region between an area enriched with clay minerals and one enriched with sulfate minerals. The mud cracks were captured in this mosaic by Curiosity’s Mastcam on June 20, 2021, the 3,154th Martian day, or sol, of the mission. The mosaic is made up of 143 images that were stitched together after being sent back to Earth.

Image Credit: U.S. Taxpayers/NASA/JPL-Caltech/MSSS/IRAP