Inevitable future: space colonization beyond Earth with microbes first

Abstract

Based on modern microbiology, we propose a major revision in current space exploration philosophy and planetary protection policy, especially regarding microorganisms in space. Mainly, microbial introduction should not be considered accidental but inevitable. We hypothesize the near impossibility of exploring new planets without carrying and/or delivering any microbial travelers. In addition, although we highlight the importance of controlling and tracking such contaminations—to explore the existence of extraterrestrial microorganisms—we also believe that we must discuss the role of microbes as primary colonists and assets, rather than serendipitous accidents, for future plans of extraterrestrial colonization. This paradigm shift stems partly from the overwhelming evidence of microorganisms’ diverse roles in sustaining life on Earth, such as symbioses and ecosystem services (decomposition, atmosphere effects, nitrogen fixation, etc.). Therefore, we propose a framework for new discussion based on the scientific implications of future colonization and terraforming: (i) focus on methods to track and avoid accidental delivery of Earth's harmful microorganisms and genes to extraterrestrial areas; (ii) begin a rigorous program to develop and explore ‘Proactive Inoculation Protocols’. We outline a rationale and solicit feedback to drive a public and private research agenda that optimizes diverse organisms for potential space colonization.

Choice of Microbial System for In-Situ Resource Utilization on Mars

“…Approaches draw from all domains of life, employing microbes as well as higher organisms, with applications ranging from production and recovery of resources, (e.g. generation of oxygen, food and materials, biomining, wastewater recycling), to providing shelter and protection, as far as generation of energy and even terraforming (Kalkus et al, 2018;Llorente et al, 2018;Hastings and Nangle, 2019;Lopez et al, 2019;Shunk et al, 2020;Volger et al, 2020).…”

Effects of Radiation Intensity, Mineral Matrix, and Pre-Irradiation on the Bacterial Resistance to Gamma Irradiation under Low Temperature Conditions

“…The assessment of the radioresistance of microorganisms makes it possible to estimate the potential duration of their cryopreservation in a viable state on various space objects, and, therefore, to select promising space bodies and their regions, as well as rocks and depths for sampling during space missions in order to study the potential habitability of these space bodies [ 6 , 9 ]. The concept of radioresistance of terrestrial microorganisms also makes it possible to interpret the data obtained during space missions from the perspective of potential habitability of alien bodies in the past and to correct existing plans for colonization of extraterrestrial territories [ 10 , 11 , 12 , 13 ].…”

Dealing with water stress and microbial preservation

“…In the present study, we address how water stress affects the survival of microorganisms at the cell level and at the ecosystem level, the mechanisms used by drought‐tolerant microorganisms to survive, their interactions with the environment under water stress, and how to use these mechanisms to improve the current techniques in preserving microorganisms. What we have learnt from microbes in nature can be used to preserve new microbial isolates and microbial consortia and communities (Prakash et al ., 2013; Lopez et al ., 2019), an issue we deal with in this minireview.…”

“…Also, in this format, it is not necessary to maintain the cold chain, so the microorganism can be sent in large quantities to remote sites with unsecured access to electricity without the need to keep the inoculums cold. It has even been proposed that this format would be appropriate for sending microorganisms outside the planet (either to the International Space Station or even to other planets) since they could resist much longer in a viable way (Lopez et al ., 2019). Using stable‐dry formats, the damages due to oxidative stress, radiation and hydrolytic reactions are reduced that otherwise would affect the viability of microorganisms.…”