A bathroom mold commonly found in warm, damp buildings and repeatedly sampled inside the International Space Station could survive under simulated conditions at the lunar south pole, according to a study published on August 19, 2026, in Science Advances.
NASA Study Finds Household Spores Could Endure Lunar South Pole Conditions
The research, led by planetary scientist Prabal Saxena of Spacedaily in Greenbelt, Maryland, examined five forms of fungi and bacteria to determine which patches of ground at the lunar south pole might fail to kill hitchhiking Earth microbes immediately.
While the lunar surface features extreme temperatures, a natural vacuum, solar and cosmic radiation, and a lack of breathable air or stable liquid water, modeling simulations indicated that certain well-shaded niches could preserve specific microorganisms in a state of suspended animation known as cryptobiosis for periods ranging from days to weeks or months.
Simulating Three Potential Human Exploration Regions
The study analyzed three specific regions under consideration for human exploration: Nobile Rim, Connecting Ridge, and De Gerlache Rim. Researchers combined topographic and temperature information from NASA’s Lunar Reconnaissance Orbiter with models of how solar ultraviolet radiation strikes the terrain.
The simulation models revealed maps of survivable niches as large as crater floors miles wide, particularly inside permanently shadowed craters and during autumn and winter seasons. Survival in the study meant staying alive for at least one Earth day, rather than growing or reproducing to form a lunar ecosystem.
The investigation tested three bacteria species (Bacillus subtilis, Staphylococcus aureus, and Deinococcus radiodurans) alongside two types of fungi (Aspergillus niger and several species of Fusarium). The two fungi studied proved hardier than the three bacteria species.
Aspergillus Niger Surpasses Known Extremophiles in UV Resistance
Among the organisms analyzed, Aspergillus niger demonstrated the highest measured resistance to ultraviolet radiation, surpassing even Deinococcus radiodurans, a bacterium routinely used as a benchmark for biological toughness due to its ability to withstand severe ionizing radiation and desiccation.
Aaron Regberg, a geomicrobiologist at NASA’s Johnson Space Center in Houston and a co-author of the paper, noted that these species are typically not considered extremophiles capable of withstanding harsh conditions like the vacuum of space. I would have expected these microbes to have dried out,
Regberg said.
Implications for Artemis Missions and Planetary Protection
The findings raise concerns regarding unintended life transfer as human space exploration continues. As the United States and China pursue plans to return astronauts to the lunar surface for the first time since 1972 and establish longer-term moon bases, visiting crews inevitably shed human-associated microbes.
Humans carry an average of 1 million bacteria on each patch of skin the size of a pencil eraser, which vent from spacesuits and habitats. Unlike robotic spacecraft, which NASA often bakes at temperatures above 400 degrees Fahrenheit to reduce living organisms, crewed missions cannot undergo the same sterilization.
Contamination could interfere with the search for chemical clues to ancient geology and biology, making it difficult to distinguish ancient lunar chemistry from human-delivered microbes. Additionally, researchers noted these microbes could affect resources such as water ice present in some lunar locations.
The study did not evaluate whether lunar conditions could cause mutations making microbes more dangerous as pathogens. However, Saxena suggested that the Moon could act as Earth’s freezer, potentially preserving evidence of Earth’s past or serving as a natural laboratory to test the real-life limits of microbial survival.
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