The transfer of unsterilized material from Mars to Phobos: laboratory tests, modelling and statistical evaluation

Publication date: Available online 20 August 2019Source: Life Sciences in Space ResearchAuthor(s): M.R. Patel, V.K. Pearson, D.J. Evans, D.J. Summers, S. Paton, P. Truscott, T. Pottage, A. Bennett, J.P.D. Gow, M.D. Goodyear, J.P. Mason, M.R. Leese, R.D. PatelAbstractSample return missions to Phobos are the subject of future exploration plans. Given the proximity of Phobos to Mars, Mars’ potential to have supported life, and the possibility of material transfer from Mars to Phobos, careful consideration of planetary protection is required. If life exists, or ever existed, on Mars, there is a possibility that material carrying organisms could be present on Phobos and be collected by a sample return mission such as the Japanese Martian Moons eXplorer (MMX). Here we describe laboratory experiments, theoretical modelling and statistical analysis undertaken to quantify whether the likelihood of of a sample from Phobos material containing unsterilized material transferred from Mars is less than 10−6, the threshold to transition between restricted and unrestricted sample return classification for planetary protection. We have created heat, impact and radiation sterilisation models based on the Phobos environment, and through statistical analyses investigated the level of sterilisation expected for martian material transferred to Phobos. These analyses indicate that radiation is the major sterilisation factor, sterilising the Phobos surface over timescales of millions of years. Th...
Source: Life Sciences in Space Research - Category: Biology Source Type: research