Water Discovered in Lunar Samples

By Jeremy Hsu
MSNBC

Water has been found conclusively for the first time inside ancient moon samples brought back by Apollo astronauts. The discovery may force scientists to rethink the lunar past and future, although uncertainty remains about how much water exists and whether future explorers could extract it.

The water was found inside volcanic glass beads, which represent solidified magma from the early moon’s interior. The news swept through much of the scientific community even before being detailed in the journal Nature this week.

“This really appears to have changed the rules of the game,” said Robin Canup, astrophysicist and director of the Southwest Research Institute in Boulder, Colo., who was not part of the team that made the discovery. “The assumption has been that the moon is dry.”

Scientists have long assumed the moon was dry because of its violent birth roughly 4.5 billion years ago. The leading theory holds that a Mars-sized planet smashed into Earth and tore off molten pieces that eventually formed into the moon. Most scientists thought that any water in the developing lunar body would have vaporized and been lost to space.

“If there was a lot of water in the early moon, then that is new for sure,” said Ben Bussey, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory who also was not involved in the new study. “People will have to think about that when they think about how the moon evolved.”

The earlier thinking about the moon’s lack of water meant researchers struggled to even get funding to search for counter-evidence.

“I thought that if we were really lucky we would get to see it,” said Alberto Saal, a geochemist at Brown University and lead author on the Nature study. “Like everybody else, I was thinking our chances were low.”

Saal’s group examined lunar samples brought back from the Apollo missions of the 1960s and 1970s. The glass beads range in color from green to yellow-brown to red, depending on their elemental chemistry.

Such beads formed from droplets of molten lava that spewed from fire fountains reaching down deep within the primitive lunar interior. Saal’s group measured the beads’ elemental makeup to ensure they came from lunar volcanic activity and not from the impact event that formed the moon.