Sept. 13 (UPI) -- For the first time, scientists have mapped the distribution of water across lunar soil. The new moon map could help scientists at NASA identify the ideal spot for a future lunar colony or research facility.
Scientists calibrated data collected by NASA's Moon Mineralogy Mapper to determine how much water and hydroxyl, a related molecule, is present beneath the lunar surface.
"The signature of water is present nearly everywhere on the lunar surface, not limited to the polar regions as previously reported," researcher Shuai Li said in a news release. "The amount of water increases toward the poles and does not show significant difference among distinct compositional terrains."
Li conducted the research while doctoral student at Brown University, but now works as a postdoctoral researcher at the University of Hawaii.
The moon isn't flush with water, by any means. The wettest lunar soil, found in the polar regions, host just 500 to 750 parts per million -- less than the dunes of Earth's driest deserts.
Still, if you're looking to establish a lunar outpost, some water is better than no water.
"This is a roadmap to where water exists on the surface of the Moon," said Ralph Milliken, an associate professor at Brown. "Now that we have these quantitative maps showing where the water is and in what amounts, we can start thinking about whether or not it could be worthwhile to extract, either as drinking water for astronauts or to produce fuel."
The new map offers clues as where the moon's water came from. Most water and hydroxyl molecules were deposited by solar wind, but a few deposits have unique origins. The map revealed higher concentrations of water in volcanic deposits near the equator, suggesting water was brought to the surface as magma erupted from the deep-lying mantle.
Data from the Moon Mineralogy Mapper also showed lower lunar latitudes get wetter in the morning and drier in the evenings.
"We don't know exactly what the mechanism is for this fluctuation, but it tells us that the process of water formation in the lunar soil is active and happening today," Milliken said. "This raises the possibility that water may re-accumulate after extraction, but we need to better understand the physics of why and how this happens to understand the timescale over which water may be renewed."
Interactions between solar winds and the lunar soil could explain the migration of water across the moon's surface.
Some scientists believed there is a significant amount of water locked up in the form of ice hiding in the bottom of lunar craters, but the Moon Mineralogy Mapper can't analyze parts of the lunar surface that remain permanently dark.
"Those ice deposits may indeed be there, but because they are in shadowed areas it's not something we can easily confirm using these data," Milliken said.
Researchers published their new map and analysis this week in the journal Science Advances.