NASA study finds Earth microbes could survive on lunar surface

The moon presents a landscape almost designed to kill. No air to breathe. Temperatures that swing from 260 degrees Fahrenheit in sunlight to far colder in shadow. Radiation that would cook unprotected flesh. This is why astronauts wear suits, why spacecraft have shielding. But there is one category of traveler that will almost certainly make the journey to the lunar surface without protection: the microbes living on human skin, in human lungs, clinging to equipment and tools.

A new NASA study suggests that some of these stowaways could actually survive there. Researchers led by planetary scientist Prabal Saxena at NASA's Goddard Space Flight Center tested five species of fungi and bacteria against simulated lunar conditions in three regions near the South Pole—Nobile Rim, Connecting Ridge, and de Gerlache Rim. The simulations, built from data collected by the Lunar Reconnaissance Orbiter and radiation measurements, revealed something unexpected: certain microbes could persist for weeks or even months in specific places, particularly inside permanently shadowed craters during the lunar autumn and winter.

The fungi proved tougher than the bacteria. Aspergillus niger, commonly known as black mold and found in warm, damp places on Earth like bathrooms and air conditioning systems, emerged as the most resilient. It has already been discovered inside the International Space Station and has survived in the vacuum of space during orbital experiments. Fusarium, a soil fungus, showed similar hardiness, though not quite to the same degree. The three bacterial species studied—Deinococcus radiodurans, Staphylococcus aureus, and Bacillus subtilis—fared worse. Ultraviolet radiation and extreme heat proved their greatest enemies, with Deinococcus showing the most tolerance and the other two struggling significantly.

The models revealed something the researchers called "survivable niches"—areas as large as crater floors stretching for miles where these microbes could endure. Aspergillus, remarkably, could survive even in regions receiving some sunlight and thus exposed to UV radiation. The biggest threats were ultraviolet light, the extreme heat of lunar day, energetic particle radiation, and the effects of the lunar vacuum itself. But there are scenarios, the researchers noted, where conditions could actually improve for these organisms. If cells became buried, they would gain protection from radiation and warmth. If pockets of liquid water formed—a possibility given that ice exists in some lunar locations—the microbes might not just survive but actually grow and reproduce.

This matters because the United States and China are planning to return humans to the moon for the first time since 1972, with NASA's Artemis program specifically targeting the South Pole region. The concern is not primarily about danger to astronauts, but about scientific contamination. The microbes hitchhiking on spacesuits and equipment could compromise the very samples scientists hope to analyze—the chemical composition of lunar soil, the presence of organic molecules, the geological record locked in rocks. As Heather Graham, an organic geochemist on the study team, explained, contamination is essentially unavoidable. Humans carry microbes everywhere. The goal now is to track what we bring so that later, when analyzing lunar samples, scientists can distinguish what came from Earth versus what belongs to the moon itself.

The study did not examine whether lunar conditions might cause mutations that could make these microbes more dangerous as pathogens, nor did it look at whether they could actually grow and reproduce on the moon—only whether they could survive. But the implication is clear: future lunar missions will need to be far more careful about what they carry, and far more rigorous about documenting it. The moon, it turns out, is not quite as sterile a destination as we once thought.