NASA | GSFC | Lunar Reconnaissance Orbiter | 2019 Mar 08
Scientists, using an instrument aboard NASA’s Lunar Reconnaissance Orbiter (LRO), have observed water molecules moving around the dayside of the Moon.
A paper published in Geophysical Research Letters describes how Lyman Alpha Mapping Project (LAMP) measurements of the sparse layer of molecules temporarily stuck to the surface helped characterize lunar hydration changes over the course of a day.
Up until the last decade or so, scientists thought the Moon was arid, with any water existing mainly as pockets of ice in permanently shaded craters near the poles. More recently, scientists have identified surface water in sparse populations of molecules bound to the lunar soil, or regolith. The amount and locations vary based on the time of day. This water is more common at higher latitudes and tends to hop around as the surface heats up. ...
Water molecules remain tightly bound to the regolith until surface temperatures peak 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. SwRI’s Dr. Michael Poston, now a research scientist on the LAMP team, had previously conducted extensive experiments with water and lunar samples collected by the Apollo missions. This research revealed the amount of energy needed to remove water molecules from lunar materials, helping scientists understand how water is bound to surface materials. ...
LAMP Instrument Sheds Light on Lunar Water Movement
Southwest Research Institute | 2019 Mar 08
Lunar Water Molecules Hop as Surface Temperature Increases
Planetary Science Institute | 2019 Mar 08
Diurnally-Migrating Lunar Water: Evidence from Ultraviolet Data ~ Amanda Hendrix et al
- Geophysical Research Letters (online 21 Feb 2019) DOI: 10.1029/2018GL081821