Micro-organisms and extraterrestrial travel

Abstract

I am taking as given that more practical means of space travel than exist now will be developed in the next century or two and that colonization — actual settlement — of extraterrestrial bodies will follow. Neither of these is certain or even close to certain, but they might happen, and if they do, problems will arise about which we had better start thinking beforehand, not during. We usually approach with a technological bias the subjects of extraterrestrial travel and possible colonization. When destinations are beyond our planet, the problem of simply getting from here to there is so intimidating that we initially think of the challenge in terms of engineering. But we may discover that the tougher problems may be biological. In our next decade spacecraft will be returning with extraterrestrial samples and more probes will be launched to get more samples than ever before. Right now we need to think at least as carefully about the life forms that may be on board space vehicles as we do about the vehicles per se. What will the organisms we will carry with us outbound do in their new environments? Also, what about the possibility that there are organisms native to the planets, asteroids, etc., to which we will travel and from which we may bring alien organisms to Earth? Will they survive here at all? Will they thrive here to our advantage or disadvantage, i.e., to the detriment of our health, food sources, and earthly ecosystems in general?