Ice may lie an inch or so below the Moon’s surface in many more regions than previously thought — which has major implications for longer-term lunar exploration or even habitation.
An India-led project found that differences in the Moon’s surface temperature vary widely, depending on location (poles versus equator), orientation (facing the Sun or not), and angle (diagonal crater walls versus flat surfaces). The lunar surface measurements were taken in 2023 by the Indian Chandrayaan-3 mission and were recently published in the journal Communications Earth & Environment.
Taking the Moon's Temperature
The measurements were the first to directly record the Moon’s surface temperature since the Apollo missions in the 1970s. Other measurements have employed remote sensing, but that data is considered both less accurate and not as effective at capturing variations based on location and geography.
But unlike those missions, the Chandra mission recorded temperatures were from several spots on the moon’s surface at multiple times of the day, while the Apollo missions primarily took temperatures near the equator.
Since the Apollo missions, others have made efforts to take the satellite’s temperature from different locations. But no mission, until Chandra, had been able to essentially stick a thermometer beneath the Moon’s surface. That may have been at least in part because previous attempts chose the wrong tools.
Read More: Ancient Celestial Objects Likely Carved Two Grand Canyons on the Moon's Surface
Probing the Moon's Crust
Earlier unsuccessful efforts tried to hammer probes into the Moon’s crust. ChaSTE, Chandra’s suite of data collection tools took a different approach: drilling a screw-like device into the ground. The Chandrayaan-3 mission employed a Vikram lander to reach Earth’s satellite and a Pragyan rover to explore its surface.
“To the best of our knowledge, ChaSTE is the first experiment to demonstrate penetration as a potential mechanism for deploying planetary thermal probes,” said the authors in the paper.
ChaSTE’s multiple measurements from 10 probes at different times showed big differences in temperatures from site to site and time to time. It recorded a high of 179.6 degrees Fahrenheit and a nighttime low of 26 degrees Fahrenheit on a slanted surface near the South Pole landing site. About a yard away, it recorded a high of 137 degrees Fahrenheit on a flatter area.
Best Spots for Lunar Ice
The lowest temperature the probes recorded was 8 degrees Fahrenheit, with a high of 188 degrees Fahrenheit. The thermal conductivity of the lunar surface acts as a blanket and stops some of the sun’s heat from penetrating into the ground.
The authors then created a model based on those measurements to help future lunar explorers better prospect for ice. They found that 14 degree or steeper slopes facing away from the sun at the pole closest to it may provide the best conditions for ice to form close to the Moon’s surface.
The poles also present good places for ice mining — good news for NASA’s manned Artemis III mission, which is aiming to land at the lunar south pole next year. However, the ChaSTE findings indicate that higher-latitude lunar regions with sufficiently sloped areas might provide easier access.
In any event, future lunar explorers now have a better idea of where they are most likely to find ice.
Read More: Scientists Are Still Pondering These Mysteries of the Moon
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
NASA. Chandrayaan-3
Communications Earth & Environment. Higher surface temperatures near south polar region of the Moon measured by ChaSTE experiment on-board Chandrayaan-3
NASA. NASA Goddard to Build Quake Detector for Artemis III Moon Landing
Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues. He began his career in newspapers, but switched to scientific magazines. His work has appeared in publications including Science News, Science, Nature, and Scientific American.
