Astronaut Microbes Might Survive at Moon's Pole, NASA Warns

One of the primary objectives of space exploration that often gets overlooked is the intense effort that goes into ensuring Earth microbes don’t contaminate planetary objects, also called forward contamination. This is done to prevent contaminating any potential life that might be present could get killed off my Earth microbes and scientists don’t want to make false discoveries. While space radiation and extreme temperatures often kill off any pesky microbes that hitch a ride on spacecraft, there remains a longstanding knowledge gap regarding whether microbes could survive the lunar polar regions due to its deep craters and varying topography. Now, a team of researchers from the NASA Goddard Space Flight Center and the NASA Johnson Space Center might be one step closer to answering whether astronaut microbes could survive the Moon’s polar regions. These findings were recently published in Science Advances and could help scientists, mission planners, and future astronauts develop methods for addressing microbes during long-term missions to the Moon and beyond. To accomplish this, the researchers analyzed several organisms that have been found on Earth and in space to ascertain whether they could survive in the lunar polar regions. These included Aspergillus niger, Bacillus subtilis, Staphylococcus aureus, Deinococcus radiodurans, and several species of Fusarium. Aspergillus niger has been sampled on the International Space Station with other experiments revealing it can survive in space. Along with space, Aspergillus niger can survive in warm, deep locations within temperature ranges of 6 °C to 47 °C (43 °F to 117 °F) but often thrives between 35 °C to 37 °C (95 °F to 99 °F). The researchers tested the resilience of these organisms in laboratory conditions designed to mimic the lunar south polar regions of Nobile Rim, Connecting Ridge, and De Gerlache Rim. They combined this data with topographic models showing the distribution of radiation across the lunar surface. In the end, the researchers found that the lunar south pole could host several locations where microbes could survive, specifically noting that Aspergillus niger could potentially survive given its resistance to ultraviolet (UV) radiation. “When we think of the Moon, we don’t typically think of biology,” said Dr. Heather Graham, who is an organic chemist at NASA Goddard whose research focuses on identifying “agnostic biosignatures”, or biology that doesn’t look like Earth’s, and is a co-author on the study. “But the Moon is a place where a cell can survive, so our first exploration of these sites should pay extra attention to our microbial hitchhikers and work hard to characterize lunar chemistry before our visits change what we will find.” NASA calls the practice of preventing “microbial hitchhikers” from traveling off-Earth as planetary protection, and it also works the opposite regarding extraterrestrial samples returning to Earth. While microbes leaving Earth and potentially contaminating another planetary body is known as forward contamination, microbes potentially returning to Earth from a planetary body is known as backward contamination. Planetary protection at NASA is managed by the agency’s Office of Safety and Mission Assurance and lists risk of contamination into Mission Categories I to V. Each category is assigned based on the mission type and the target’s potential for hosting life with I being the lowest risk and V being the highest risk of contamination. As the study emphasizes, NASA plans to return astronauts to the lunar surface in the next few years through the agency’s Artemis program with the goal of establishing a permanent Moon base at the lunar south pole. Recognizing how to prevent microbes from contaminating lunar regions could enable greater scientific discoveries and maximum crew safety, too. What new insights into microbes surviving the lunar poles will researchers make in the coming years and decades? Only time will tell, and this is why we science! As always, keep doing science & keep looking up!