Image Courtesy: NASA
Some microbes carried to the Moon by astronauts could survive in sheltered areas near the lunar South Pole, potentially complicating future efforts to study the Moon’s pristine chemistry and search for evidence of life, according to a NASA-led study published in Science Advances on Aug. 19.
The researchers found that certain bacteria and fungi could remain alive in small, protected lunar environments, with some potential refuges measuring no more than an astronaut’s footprint. The findings raise new concerns about biological contamination as human missions establish a more sustained presence on the Moon, according to NASA.
Humans inevitably bring microorganisms into space. Some can escape from spacesuits, spacecraft, and habitats despite extensive sterilization. This could make it difficult for scientists to determine whether biological or chemical material detected during future missions originated on the Moon or was transported there by humans.
The team examined five types of microbes, including Aspergillus niger, Bacillus subtilis, Staphylococcus aureus, Deinococcus radiodurans, and several Fusarium species. The organisms were selected because they are associated with humans or have previously demonstrated an ability to withstand spaceflight conditions.
The researchers combined laboratory data on microbial tolerance to heat and ultraviolet radiation with environmental models of three areas near the lunar South Pole: Nobile Rim, Connecting Ridge, and De Gerlache Rim. The models used elevation and temperature measurements from NASA’s Lunar Reconnaissance Orbiter.
The results revealed potential “survivable niches” ranging from large crater floors to tiny patches of protected terrain. Aspergillus niger was particularly resilient and could potentially survive even with some exposure to sunlight because of its resistance to ultraviolet radiation.
However, survival does not mean the microbes could reproduce. The study indicates that some organisms might persist in a dormant state, but the Moon lacks key conditions needed for sustained growth, particularly liquid water.
Prabal Saxena, the study’s lead scientist at NASA’s Goddard Space Flight Center, said humans inevitably bring microbes wherever they explore. Researchers now hope to use the Moon’s extreme environment as a natural laboratory for studying how long those organisms can persist.
The findings could also become important for Mars exploration. Scientists will need to distinguish potential signs of extraterrestrial life from microorganisms accidentally transported from Earth, making contamination control increasingly important as human exploration expands beyond the Moon.
