When you think of the Moon, the adjective "damp" generally doesn't spring to mind.

Earth's natural satellite is known to be very dry; a gray ball of gunpowder-scented dust and ancient volcanic rock. It's been a long time since anyone thought there might be an ocean of liquid water up there.

Yet the Moon isn't as devoid of water as appearances suggest… and early in its history, it may have been wetter still.

According to a new analysis of a meteorite determined to have originated on the Moon, the lunar crust was once far richer in water than we previously thought. A team led by lunar geoscientist Tara Hayden of the University of Western Ontario found a mineral therein that suggests the lunar crust was rich in volatile elements 4 billion years ago, including water.