Speaking of water, NASA-funded research has found that the amount in the Moon has been severely underestimated. The total could be greater than America's Great Lakes. We have known that the lunar regolith contains small amounts of water. It was thought to have arrived in small amounts via meteorites and the solar wind. The new data indicates that water exists in large amounts in, and has been there since the Moon's formation. Estimates range from 50 to 5000 parts per billion. Multiplied by the Moon's mass of 7.3 x 10^22 kg, there could be 10^14 kg of water in the Moon!Whenever humans do return to the Moon, they will need to live off the land. A typical cubic meter of regolith contains about one quart of water. The lunar poles could contain even more locked up as ice. Data from the Lunar Laser Ranging Experiment also indicates a changing speed of light.Water and other mysteries are ample reasons for humans to explore the Moon.