Water Discovered on the Moon's Surface

Samples of lunar rocks brought back to Earth by Apollo astronauts had never shown any signs of water, leading scientists to presume that the moon was bone dry, except for possible pockets of water ice in permanently shadowed craters at the moon's south pole.

But the new observations, from India's Chandrayaan-1 satellite, NASA's Cassini spacecraft and NASA's Deep Impact probe call into question 40 years of assumptions on the make-up of the lunar surface

A trio of satellites—including India's recently failed lunar probe, Chandrayaan-1—picked up the light signature of water (H2O) or hydroxyl (OH) or both while mapping the moon.

The other two probes that found moon water are NASA's Cassini and Deep Impact spacecraft.

But don't go planning a lunar pool party just yet: The water or hydroxyl molecules on the moon are bound to other molecules and exist in trace amounts over the entire lunar surface.