What Do We Know About Mars Based on All Mars Exploration Missions?

More than 50 years of robotic missions have changed Mars from a telescopic mystery into the most closely studied planet beyond Earth. The combined record from orbiters, landers, rovers, atmospheric probes, and radar instruments shows that Mars once had rivers, lakes, groundwater systems, volcanoes, impact basins, polar ice, dust storms, weather, and chemical environments that could have supported…