NASA's LRO spacecraft observes water on Moon's surface

NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft has observed signs of water on the day side of the Moon, which could be an important discovery for the space agency's plans to send astronauts to the lunar surface again.

Lyman Alpha Mapping Project (LAMP) -- the instrument aboard LRO -- managed to measure the sparse layer on molecules temporarily stuck on the surface of Earth's natural satellite. This also helped astronomers characterize lunar hydration changes over the course of a day.

"The study is an important step in advancing the water story on the Moon and is a result of years of accumulated data from the LRO mission," said John Keller, LRO deputy project scientist from NASA's Goddard Space Flight Centre.

Previously, it was believed that the Moon only had water in pockets of ice in permanently shaded craters near the poles. However, recent studies showed that surface water was present in sparse populations of molecules bound to the lunar soil.

Scientists believe that the hydrogen ions in the solar wind might be the source of most of the Moon's surface water. However, the water observed by LAMP doesn't decrease when the Moon goes behind the Earth, meaning the water increase as time passes instead of raining down from the solar wind.

"These results aid in understanding the lunar water cycle and will ultimately help us learn about accessibility of water that can be used by humans in future missions to the Moon," said lead author Amanda Hendrix.

"Lunar water can potentially be used by humans to make fuel or to use for radiation shielding or thermal management; if these materials do not need to be launched from Earth, that makes these future missions more affordable," Hendrix added.