Scientists with the Laboratory for Atmospheric and Space Physics (LASP) a the University of Colorado at Boulder think the Moon may be awash in far more water than scientists previously believed, reports Universe Today.
LASP researchers created computer models to recreate conditions early in the Moon’s history. They discovered that ancient lunar volcanoes spewed huge volumes of water vapor, which settled to the surface. In craters near the poles that are permanently exposed to the heat of the sun, the water froze froze. The study suggests that the water could measure dozens or even hundreds of feet thick in places.
“It’s possible that 5 or 10 meters below the surface, you have big sheets of ice,” says co-author Paul Hayne. “It’s a potential bounty for future moon explorers who will need water to drink and process into rocket fuel.”
The study builds on previous work that estimated 25,000 square miles of the lunar surface could be capable of trapping and hanging onto ice.
In 2018 scientists documented the first evidence of water ice on the Moon that was trapped in the bottom of craters at the north and south poles locked in perpetual shadow. Discovery of the ice created new questions. While the craters are protected from direct sunlight, they aren’t shielded from solar wind. The ionized particles from the Sun is highly erosive and, unlike the Earth, the Moon has no magnetic shield to protect it. By some peoples’ reckoning, the solar wind should have destroyed the ice long ago.
In research presented at the Lunar and Planetary Science Conference last month, University of Arizona scientists shared their map of magnetic anomalies, regions of the lunar surface with unusually strong magnetic fields, reports LiveScience.
These anomalies may serve as tiny magnetic shields.”These anomalies can deflect the solar wind,” Lon Hood, a planetary scientist at the University of Arizona, told Science. “We think they could be quite significant in shielding the permanently shadowed regions.” more “Do Small Magnetic Fields Protect Pockets of Lunar Ice?”
Scientists who have modeled 4 billion years of the Moon’s meteor-impact history have concluded that the Moon holds more water than previously believed. Much of it is buried, as much as 10 meters deep.
“We looked at the entire time history of ice deposition on the Moon,” said Keven Cannon, a planetary scientist at the Colorado School of Mines and lead author of the study in Geophysical Research Letters. “If the coldest regions have been stable and accumulating ice for billions of years, then some could have very substantial deposits, but they might be buried up to 10 meters deep or more.” more “Moon May Contain Billions of Tons of Buried Ice”
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”
Looking for creative approaches to tap lunar resources to meet the needs of astronauts on the Moon, NASA has reached out to small businesses and nonprofit research institutes for ideas. Working through its small business programs, the agency has winnowed down 409 proposals for Phase 1 development.
Consistent with NASA’s goals for Project Artemis, the proposals are focused on extraction and processing of water ice from lunar regolith to create oxygen, drinking water and rocket fuel, according to Universe Today.
Water is essential to space exploration and colonization. Now that it has been demonstrated that billions of gallons of ice and molecular water are found on the Moon, the challenge is to figure out how to extract it.
In MIT Technology Review, space reporter Neel V. Patel lists the obstacles. Super-cold temperatures and radiation could endanger humans and degrade equipment. Lunar dust sticks to everything, wrecking machinery and posing safety issues to workers in spacesuits. And, of course, astronaut miners would have to be housed and supported on the Moon.
Lunar water comes in the form of tiny icy grained mixed with the soil, mostly in permanently shaded regions of craters in temperatures of 40 K (-233.15 °C). To be useful as a rocket fuel the material, only 5.6% water by weight, would require aggressive processing to rid contaminants.
One proposed method would be to build large towers with concave mirrors on the top that could reflect sunlight into the shadowed regions of lunar craters trapping the water. The energy would heat the lunar soil enough to get the ice to sublimate into vapor. A tent (transparent so the light could get through) would capture the vapor, which could be moved into units where it would freeze back into ice, and then purified at a separate location. Ultimately, the water would be separated into oxygen and hydrogen by electrolysis, and then liquified to the constituents used as rocket propellant.
Although humans have demonstrated the ability to operate rovers and landers that can withstand conditions on the Moon, no one knows if industrial infrastructure would hold up. Writes Patel: “It’s not easy to just wake a piece of technology from a 40 K slumber.” more “How to Extract Ice on the Moon”
A paper published in the January 2020 issue of Icarus examines the relationship between the age of lunar craters and the abundance of surface ice. Surface ice at the lunar south pole is found predominantly in ancient craters, 3.1 billion years or older. Some smaller, newer craters also host surface water. But surface icy is “very patchy” in spatial distribution, suggesting high overturn or destruction rates by meteor and micrometeor bombardment.
“The majority of surface ice is contained in old craters ≥∼3.1 Gyr, where the majority of cold-trapping area on the pole exists. The ice [in] these ancient craters is very patchy in surficial distribution, occupying <11.5% of cold-trapping surface area available in individual craters. This patchy distribution of ice in old craters is likely to be due to impact bombardment and regolith overturn within the polar regions. more “Correlating Water Resources with Crater Age”
The Moon may not have an atmosphere, but it does have “weather” after a fashion. Researchers have found that the particles in solar wind appear to interact with the Moon in an unexpected way, reports the Daily Mail.
The solar particles interact with the Earth’s magnetic field to create the aurora borealis. But the Moon lacks a magnetic field, so scientists thought it passively absorbed the solar wind. But measurements made by Indian’s Chandrayaan-1 lunar orbiter have revealed that 10% of the solar wind is reflected back into space, creating turbulence as solar wind streams past the Moon. Vortexes billow onto the dark side of the Moon.
Charles Lue, a researcher at the Swedish Institute of Space Physics, has found that the reflection of solar wind varies with localized magnetic fields on the lunar surface.
Explains the Daily Mail:
In areas with strong magnetism, caused by iron in the crust, the solar wind flow is restricted, while adjacent areas receive increased flow. This results in unusual spirals of ions streaming off the dayside of the moon, where the solar wind strikes first, to the nightside.
The weathering of the moon’s surface by the solar wind may be less than previously predicted, which could mean there is less water hidden beneath the crust. Said Lue: “The reduced solar wind weathering allows us to separate micro-meteorite and solar wind-inducing weathering, including the effects of different solar wind species, differently well shielded.”
The SpaceTrex lab at Arizona State University is partnering with NASA to create a tiny satellite, called the CubeSat, designed to measure and locate water on the Moon in the Lunar Polar Hydrogen Mapper or “Luna-H Map” project.
The competition is intense to be included on mission payloads. CubeSats are small enough, writes Popular Science, that they can hitch rides on rockets with larger payloads and get released on their own trajectories to conduct their own science. The first official launch of NASA’s Space Launch System and Orion spacecraft, scheduled for 2018, will carry 11 separate CubeSat missions into deep space, including one that will measure the effects of space radiation on yeast. The spacecraft will drop off LunaH-Map potentially along with two other lunar CubeSats to settle the question of how much water there is on the Moon and where it is.
The question for lunar water has strategic significance that the other scientific endeavors, as interesting as they may be, do not have. As Popular Science notes, lunar water will fuel exploration deeper into the solar system.
Jekan Thanga, the head engineer on LunaH-Map, dreams of a lunar gas station for astronauts. “Just think, we could have a refueling station at the L2 point,” he says, referring to a point beyond the Moon where gravitation alignments would allow supplies in space to remain stationary. “Our astronauts could stop there to refuel and stock up on supplies before heading out to Mars, or Europa.”
Since 2000 more than 300 CubeSat missions have been deployed in Earth Orbit, including the Planetary Society’s LightSail this year.