Earth Microbes Can Survive Seven Days in Lunar Shadows, NASA Study Finds
Research suggests the Moon's south pole provides a radiation refuge for terrestrial fungi and bacteria, raising contamination risks for future missions.
Common Earth microbes can survive for up to seven days in the permanently shadowed regions of the lunar south pole, according to a NASA-led study. The findings suggest that specific polar environments are far less hostile to terrestrial life than previously assumed.
Published August 19, 2026, in Science Advances, the research utilized data from the Lunar Reconnaissance Orbiter to model surface conditions. The study identified that the Moon's permanently shadowed regions (PSRs) act as a shield, protecting microorganisms from the lethal ultraviolet radiation that scours most of the lunar surface. While these organisms are not actively growing or reproducing, they persist in a dormant "cryptobiotic" state.
Among the tested organisms, the fungus Aspergillus emerged as the most resilient. Prabal Saxena, a research space scientist at NASA Goddard Space Flight Center who led the study, noted that Aspergillus was the "champion" of the group. Saxena attributed this resilience to the fungus's thick cell walls and dark pigments, which provide critical protection against UV-C radiation, X-rays, and cosmic radiation.
The Polar Refuge
The lunar south pole has become a primary target for international space efforts, including NASA's Artemis program and a joint Chinese-Russian partnership. This interest is driven by the presence of PSRs, which are believed to harbor water ice. Unlike the rest of the Moon, which is subject to extreme temperature swings and intense solar exposure, these deep shadows provide a stable thermal and radiation refuge that can sustain terrestrial biological matter for a limited window.
Implications for Exploration
The ability of Earth-based microbes to persist on the lunar surface introduces significant "forward contamination" risks. If human-associated bacteria or fungi survive near landing sites or ice-extraction zones, they could create biological noise that compromises the search for genuine extraterrestrial chemical or biological signatures.
This discovery may force mission planners to overhaul current planetary protection strategies. To prevent the formation of biological archives in lunar shadows, agencies may need to implement stricter sterilization protocols for spacecraft, designate specific "dirty" zones for equipment, and redesign habitat hygiene systems to ensure that Earth's microbiome does not permanently colonize the lunar poles.
Future Outlook
While the study confirms the possibility of short-term survival, the long-term viability of these microbes remains a subject for further research. Scientists will now need to determine if these dormant states could be reactivated or if they pose a permanent risk to the scientific integrity of the lunar south pole as human presence increases.