The Stratospheric Observatory for Infrared Astronomy (SOFIA) has detected evidence of molecular water in the regolith of Clavius Crater, a large crater visible from Earth in the Moon’s southern hemisphere. The airborne SOFIA observatory, a partnership between NASA and the German Aerospace Center, flies in a modified Boeing 747SP aircraft above the atmospheric water that blocks ground observation.
Satellites have had detected “hydrates” in the lunar regolith but could not distinguish between OH (hydroxyl) and H20 (molecular water). SOFIA was able to measure the precise being vibration of the H-O-H molecular bond at 6.1 µm in the infrared.
SOFIA targeted high lunar latitudes near the South Pole where low temperatures could allow migrating water to transiently remain on the surface and high hydroxyl abundances could create and trap water when impacted by small meteorites. Although Clavius has a relatively high concentration of water by lunar standards, says NASA, it is roughly one-hundredth of the water found in the Sahara desert. more “Molecular Water Found in Clavius Crater”
It has been an enduring mystery why the side of the Moon facing the Earth is marked by large dark patches, called maria (or seas, as they once were thought to be) but the far side has very little. Thirty-one percent of the near side consists of maria, but the dark side has only one percent. The maria, which are vast plains of basalt, most likely were formed by volcanic activity early in the Moon’s history.
But why the disparity between the near side and the far side? Scientists think that a clue resides in the distinctive characteristics of the rock. Based on samples that Apollo astronauts brought home from the maria, scientists found that the rock had a unique signature, which they named KREEP — for the presence of potassium (chemical symbol K), rare-earth elements (which include cerium, dysprosium, erbium, europium and others), and phosphorous (chemical symbol P) — as well as uranium and thorium.
By melting KREEP rock in high-temperature experiments, scientists from Tokyo’s Earth‐Life Science Institute (ELSI), the University of Florida, the Carnegie Institution for Science, Towson University, NASA Johnson Space Center and the University of New Mexico think that radioactive decay of some of these elements released heat that could have influenced the timing and volume of volcanic activity.
According to Phys.Org, potassium, thorium and uranium are radioactively unstable elements. appearing in a wide variety of isotopes. When the atoms break down, they yield other elements and produce heat. The heat from this radioactive decay can melt the rocks they are contained in.
Says EKSI’s Matthieu Laneuville: “Because of the relative lack of erosion processes, the moon’s surface records geological events from the solar system’s early history. In particular, regions on the moon’s near side have concentrations of radioactive elements like U and Th unlike anywhere else on the moon. Understanding the origin of these local U and Th enrichments can help explain the early stages of the moon’s formation and, as a consequence, conditions on the early Earth.”
Silver hydroxide molecules released from silicon dioxide in the lunar regolith react easily with hydrogen, leading to the formation of water and silver, scientists with the Higher School of Economics and the Space Research Institute of the Russian Academy of Sciences have found.
The implication is that water and silver molecules can be formed on the Moon. In some areas, the proportion of water formed by this mechanism could exceed 6 to 10%.
“The study demonstrates that water may form due to internal, continuously functioning mechanisms. (Comets hitting the lunar surface is a rather rare phenomenon.) It turns out that the water on the Moon can be present not only in cold traps but also in the near-surface lunar soil,” explained Sergey Popel, a study author and head of the laboratory at the Space Research Institute.
Also, said Popel, the presence of water can affect the phototelectric properties of the lunar regolith and the parameters of the plasma-dust system over the Moon.
The Moon’s thin atmosphere contains neon, NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft has confirmed.
“The presence of neon in the exosphere of the moon has been a subject of speculation since the Apollo missions, but no credible detections were made,” said Mehdi Benna of NASA’s Goddard Space Flight Center in Greenbelt, Maryland and the University of Maryland, Baltimore County in a NASA press release. “We were very pleased to not only finally confirm its presence, but to show that it is relatively abundant.”
Because the Moon’s atmosphere is so tenuous, about 100 trillion times less dense than Earth’s atmosphere are sea level, the volume of neon is minute.
Most of the gases in the exosphere — primarily neon, argon, and helium — comes from the solar win, a stream of electrically conducting gas blown from the surface of the sun into space at about one million miles per hour. All of these elements impact the Moon, but only helium, neon and argon are volatile enough to return to space. A portion of the helium, argon, and neon in the lunar exosphere comes from naturally occurring radioactive potassium-40, thorium, and uranium found naturally in lunar rocks. more “Neon Found in Lunar Atmosphere”