Washington: Scientists, using data from an instrument which flew aboard India’s Chandrayaan-1 spacecraft, have created the first map of water trapped in the uppermost layer of the moon’s soil, which may prove useful for future lunar explorers.
The study, published in the journal Science Advances, builds on the initial discovery in 2009 of water and a related molecule – hydroxyl, which consists of one atom each of hydrogen and oxygen – in the lunar soil.
Scientists from the Brown University in the US have used this data to quantify how much water is present on a global scale. “The signature of water is present nearly everywhere on the lunar surface, and is not limited to the polar regions, as previously reported,” said Shuai Li, a former PhD student at Brown University.
The water concentration reaches a maximum average of around 500 to 750 parts per million in the higher latitudes. That is less than what is found in the sands of Earth’s driest deserts, researchers said. “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,” said Milliken.
The researchers said that the way the water is distributed across the Moon gives clues about its source. The distribution is largely uniform rather than splotchy, with concentrations gradually decreasing toward the equator.
Although the bulk of the water mapped in this study could be attributed to solar wind, there were exceptions. For example, the researchers found higher-than-average concentrations of water in lunar volcanic deposits near the Moon’s equator, where background water in the soil is scarce.