The moon, long thought to be bone dry, actually contains a surprising amount of water. In the latest twist, these stores turn out to be just like those on Earth, and probably filled by the same source: ancient asteroids.
Moon samples had the same hydrogen-deuterium ratio as found in asteroids and Earth’s oceans. The simplest explanation, says Saal: The moon’s water was on Earth at the time of the giant impact.
knowledge of self 