spacetoday.net: Discovery of water in lunar interior may alter models of Moon's formation

Posted: Fri, May 27, 2011, 7:53 AM ET (1153 GMT)
Scientists have discovered traces of water in rocks from the Moon's interior, a discovery that may force a reexamination of the current leading explanation for the Moon's formation. Researchers measured the water content of tiny globules of molten rock encased in crystals of so-called "orange glass soil" returned from the Moon on the Apollo 17 mission. The globules, from the Moon's interior, contain 100 times the water previously expected, and similar to the water content of the Earth's upper mantle. The finding may be in conflict with the "giant impact" model of the formation of the Moon, where a Mars-sized protoplanet collided with the proto-Earth, throwing off material that later coalesced to form the Moon. That model predicts a very low water content for lunar rocks because of outgassing during the collision and formation process. The discovery may also provide an alternative explanation for water ice deposits found at the lunar poles.