WASHINGTON — One of the biggest lunar discoveries of the decade — proof that the moon may have had water since its formation — was announced Wednesday by a team of researchers.
In an article published in the journal Nature, the six-scientist team of geologists and geochemists showed that water from the moon's interior gushed to the surface more than 3-billion years ago in geyserlike jets of molten magma, disproving a long-standing belief that Earth's nearest neighbor is almost bone-dry.
The source of their discovery: two one-gram samples of moon rocks brought back to Earth more than 35 years ago by the Apollo 15 and Apollo 17 lunar missions.
"It's a real step forward, and it shows we're still getting things out of the Apollo samples," said NASA's David Lindstrom, a program officer and a lunar scientist since Apollo 11.
Alberto Saal, a geochemist at Brown University and the study's lead author, said he was inspired by breakthroughs in the technology that enables scientists to detect minute traces of water in rock. "It was almost a no-brainer to go and see," he said.
The researchers think that water vapor was part of volcanic eruptions from the moon's core that quickly solidified on its icy surface.
"It really changes the rules of the game as to what we're assuming about the moon," said Robin Canup, a leading lunar history expert.