NASA's Phoenix Mars Lander has detected snow falling from Martian clouds. Spacecraft soil experiments also have provided evidence of past interaction between minerals and liquid water, processes that occur on Earth.
A laser instrument (the Canadian-designed lidar) designed to gather knowledge of how the atmosphere and surface interact on Mars has detected snow from clouds about 4 kilometers (2.5 miles) above the spacecraft's landing site. Data show the snow vaporizing before reaching the ground. Read more at the Jet Propulsion Labs (JPL).