Deep Space Gateway Science Workshop 2018 (LPI Contrib. No. 2063)

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The Moon: A 100% isolation barrier for Earth during exobiological examination of solar system
sample return missions. Barry E. DiGregorio, Buckingham Centre for Astrobiology, University of
Buckingham, Buckingham MK18 1EG, United Kingdom
Introduction: In the coming decades NASA and all other capable space faring nations will want toreturn 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 accidental contamination of the Earth’s biosphere remain
problematic. For example, robotic sample return missions that are sent to the surface of the Earth or Earthorbit for laboratory analysis do not offer a 100% guarantee that some technological or other errors would
not lead to an eventual exposure of these materials to Earth’s biosphere. Even if examined in an Earthorbiting space station, a contamination event might render it uninhabitable, ultimately to reenter theEarth’s atmosphere where sections of the spacecraft could survive intact and spread out over vastdistances of our planet.
The only 100% guarantee of protecting Earth’s biosphere from a hazardous back contamination event isto 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. Asidefrom 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 ofan 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 backcontamination 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 Earthenvironments.
Finally, other advantages would be experiments on the mutation rates of terrestrial microorganisms in thelunar 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.

References:Bionetics Corporation. (1988) Lessons Learned from the Viking
Planetary Quarantine and Contamination Control Experience,
contract NASW-4355, the Bionetics Corporation,Hampton, VA.

Committee on the Planetary Science Decadal Survey. (2012)

Deep Space Gateway Science Workshop 2018 (LPI Contrib. No. 2063)

Vision and Voyages for Planetary Science in the Decade2013–2022, National Academies Press, Washington, DC.

Levin, G.V. and Straat, P.A. (2016) The case for extant life onMars and its possible detection by the Viking labeled release
experiment. Astrobiology 16:798–810.

McKay, C.P., Porco, C.C., Altheide, T., Davis, W.L., and Kral,T.A. (2008) The possible origin and persistence of life on Enceladusand detection of biomarkers in the plume. Astrobiology
8:909–919.

NRC, A Science Strategy for the Exploration of Europa (1999)
ISBN 0309064937, Committee on Planetary and Lunar Exploration,
National Research Council.

NRC, Preventing the Forward Contamination of Europa (2000)
ISBN NI000231, Task Group on the Forward Contamination ofEuropa, Space Studies Board, National Research Council.

UN OOSA A/72/20. (2017) Report of the Committee on thePeaceful Uses of Outer Space (COPUOS 60th Session), para
332. United Nations, New York.

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