Until the last decade, scientists thought that water did not exist on the surface of the moon and that even if it did, it was mostly in the form of ice in permanently shaded craters near the poles. However, NASA’s Lunar Reconnaissance Orbiter or LRO has been able to detect water molecules moving around the dayside of the Moon.
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.” The amount and location of the water molecules varied based on the time of day, that is, there is no fixed spot or time where and when the LRO detected water molecules. At higher latitudes, lunar water is pretty common and the molecules tend to hop around as the surface heats up. – John Keller, the LRO deputy project scientist from NASA’s Goddard Space Flight Centre in Maryland
The new discovery could not have been more convenient as NASA is currently planning on sending astronauts back to the surface of the Moon. The instrument aboard the LRO, Lyman Alpha Mapping Project (LAMP), measured a sparse layer of molecules temporarily stuck to the Moon’s surface. A paper published in the Geographical Research Letters reveals that the measurement done by the LAMP actually helped to characterize lunar hydration changes over the course of a day.
These results aid in understanding the lunar water cycle and will ultimately help us learn about the accessibility of water that can be used by humans in future missions to the Moon. 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. – Amanda Hendrix, a senior scientist at the Planetary Science Institute
Scientists indeed have come up with an explanation. They are of the opinion that hydrogen ions in the solar wind may be the source of most of the Moon’s surface water. Consequently, when the Moon passes behind the Earth and is shielded from the solar wind, the “water spigot” gets turned off. However, the water does not decrease when the Moon is shielded from the solar wind behind Earth, rather, the water builds up over time.