Scientists observed water molecules around the day side of the Moon via NASA’s Lunar Reconnaissance Orbitor (LRO). The step would serve to seek water availability in that region to enable the resource for humans in future lunar expeditions.
Lunar hydration changes over the course of a day were observed in depth via LAMP (Lyman Alpha Mapping Project) measurements of the sparse layer of molecules that temporarily stuck to the surface, describes the research paper published in Geophysical Research Letters.
Moon was considered to be parched till the last decade, with any water existing mainly as pockets of ice in permanently shaded craters near the poles. In recent research, scientists identify the existence of surface water in sparse populations of molecules bound to the lunar soil, or regolith, mentions NASA in a statement.
Variation in the quantity and locations might be observed at different intervals of the day. This water is likely to be available more at higher latitudes and tends to hop around as the surface heats up.
Amanda Hendrix, a senior scientist at the Planetary Science Institute, states “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,” says Hendrix.
“This is an important new result about lunar water, a hot topic as our nation’s space program returns to a focus on lunar exploration,” said Dr. Kurt Retherford, the principal investigator of the LAMP instrument from Southwest Research Institute in San Antonio, Texas. “We recently converted the LAMP’s light collection mode to measure reflected signals on the lunar day side with more precision, allowing us to track more accurately where the water is and how much is present.”
Water molecules remain tightly bound to the regolith till the peak surface temperature is reached, near-lunar noon. Then, molecules thermally desorb and can bounce to a nearby location that is cold enough for the molecule to stick or populate the Moon’s extremely tenuous atmosphere or exosphere until temperatures drop and the molecules return to the surface.
Having conducted extensive experiments earlier with water and lunar samples collected by the Apollo missions, Dr. Michael Poston, a research scientist on the LAMP team, reveals through his recent research the amount of energy needed to remove water molecules from lunar materials. This shall help scientists to understand how water is bound to surface materials.
“Lunar hydration is tricky to measure from orbit, due to the complex way that light reflects off of the lunar surface,” said Dr. Michael Poston.
He continues, “Previous research reported quantities of hopping water molecules that were too large to explain with known physical processes. I’m excited about these latest results because the amount of water interpreted here is consistent with what lab measurements indicate is possible.”
Earlier, scientists mention in their hypotheses that the hydrogen ions in the solar wind may contribute as a major source of the Moon’s surface water.
As the Moon passes behind the Earth, gets shielded from the solar wind, the “water spigot” essentially turns off, scientists observed.
The water observed by LAMP, however, behaves differently. It does not decrease when the Moon is shielded by the Earth i.e. this sample of water doesn’t erupt directly as a result of solar wind. Its the influence of the regional magnetic field which results in water builds up over time.