The Moon may hold much more water than we think

Scientists have long suspected the Moon holds sizable reserves of water, secreted as ice in the deep cold of permanently shadowed craters near the poles. Two new studies tell us more about the possible extent of those reserves. One suggests the shadowy polar caches may cover an area equivalent to the states of Connecticut and Massachusetts combined; the other reveals traces of water elsewhere on the Moon’s surface, trapped in rocks or between the grains of lunar soil. That’s welcome news for NASA, which plans to return astronauts to the lunar surface in 2024 as a first step toward a permanent outpost and eventual journeys to Mars.