Precipitation Groundwater Water Resources Water Cycle Water Vapor Water Scarcity Flooding Water Cycle Processes Weather Systems Water Vapor Dynamics Hydrothermal Processes Hydrothermal Systems Climate Impact Studies Water Origins Water Vapor Transport Rain Measurement Seismology Terrestrial Water Storage Water Quality Dams River Systems Surface Water Aquifers Ephemeral Lakes Snowpack Measurement Water Management Freshwater Cycle Water Balance Snow Water Storage Water Sources Precipitation Patterns Rivers Flood Complexity Freshwater Bodies Water Depth Lake Formation Water Measurement Colorado River System Lake Depth River Water Storage River Basins Research Methods Water Crisis River Flows River Stores Research Methodology Findings River Flow Flooding Phenomena Future Implications Lake Dynamics Fresh Water Hydrological Cycle Meltwater River Dynamics Water Resources Management
Simulations show rain and snow likely formed Martian valleys, but the planet's ancient heat source remains a mystery.