Barry DiGregorio spent ten years as a Research Associate for Cardiff Centre of Astrobiology at Cardiff University in Wales from 1999 to 2010. From 2010 to 2016 DiGregorio was a writer for The American Society of Microbiology magazine MICROBE. In 2010 to 2018 Barry was made an Honorary Research Fellow for Buckingham University’s Centre for Astrobiology in the UK. Today he isretired and resides near Lake Ontario in the state of New York.

Introduction: In the coming decades NASA and all other capable space faring nations plan to return samples of Mars, samples of ice from Jupiter’s moon Europa and samples of the plumes of water emanating into space from Saturn’s Moon Enceladus to look for any evidence of extraterrestrial biology. As exciting as these sample

return missions are to astrobiologists, lingering questions on how best to safely examine these samples without accidentally contaminating Earth’s biosphere remain problematic. For example, robotic sample return missions that are sent to the surface of the Earth or Earth orbit for laboratory analysis do not offer any guarantees that some technological or other failures would not lead to exposure of these materials to Earth’s biosphere. Even with an Earth orbiting space station, a contamination event might render it uninhabitable, ultimately to reenter the Earth’s atmosphere where sections of the spacecraft could survive intact and spread out over vast distances of our planet. The only guarantee of protecting Earth’s biosphere from a hazardous back contamination event is to use the Moon as a sample return examination facility to qualify samples for

eventual return to Earth. A well planned lunar quarantine laboratory as part of a larger lunar base would be perceived by the public and scientific community as another legitimate reason to reinvest in a return to the Moon. Pros: The size of sample return payloads could be much larger because of the Moons 1/3 gravity. Aside from the

Moon offering a 100% back contamination barrier to Earth, it also has enough gravity that would make working with extraterrestrial materials less difficult than working in a microgravity environment of an orbital space station or other orbiting module designed for such a purpose. The Moon’s lack of an atmosphere with near vacuum conditions greatly reduces the possibility of the spread of a back

contamination event to other areas of a lunar scientific outpost. If putative extraterrestrial microorganisms are found in samples, a lunar planetary quarantine facility could be used to test a wide variety of terrestrial ecosystems in enclosed modules simulating various Earth environments. Finally, other advantages would be experiments on the mutation rates of terrestrial microorganisms in the lunar radiation environment that might help how humans could

best survive radiation exposure on Mars.

Cons: Cost. Obviously the establishment of a lunar quarantine facility as part of large scientific outpost would require the commitment and resources from a number of space faring partners