“One can imagine an ancient lake filling the crater in which these mounds are located, the shoreline changing as the sea level varied with the Martian climate, the tides leaving behind alternating layers of mudstone and limestone.”
Mars
Mars Curiosity Rover Collects Rock Samples Containing Key Ingredient Of Life
Rock samples collected from Mars by NASA’s Curiosity rover have revealed signs of key ingredients of life, according to a statement by the agency.