Earth as a Tool for Astrobiology—A European Perspective

Abstract

Scientists use the Earth as a tool for astrobiology by analyzing planetary field analogues (i.e. terrestrial samples and field sites that resemble planetary bodies in our Solar System). In addition, they expose the selected planetary field analogues in simulation chambers to conditions that mimic the ones of planets, moons and Low Earth Orbit (LEO) space conditions, as well as the chemistry occurring in interstellar and cometary ices. This paper reviews the ways the Earth is used by astrobiologists: (i) by conducting planetary field analogue studies to investigate extant life from extreme environments, its metabolisms, adaptation strategies and modern biosignatures; (ii) by conducting planetary field analogue studies to investigate extinct life from the oldest rocks on our planet and its biosignatures; (iii) by exposing terrestrial samples to simulated space or planetary environments and producing a sample analogue to investigate changes in minerals, biosignatures and microorganisms. The European Space Agency (ESA) created a topical team in 2011 to investigate recent activities using the Earth as a tool for astrobiology and to formulate recommendations and scientific needs to improve ground-based astrobiological research. Space is an important tool for astrobiology (see Horneck et al. in Astrobiology, 16:201-243, 2016;Cottin et al., 2017), but access to space is limited. Complementing research on Earth provides fast access, more replications and higher sample throughput. The major conclusions of the topical team and suggestions for the future include more scientifically qualified calls for field campaigns with planetary analogy, and a centralized point of contact at ESA or the EU for the organization of a survey of such expeditions. An improvement of the coordinated logistics, infrastructures and funding system supporting the combination of field work with planetary simulation investigations, as well as an optimization of the scientific return and data processing, data storage and data distribution is also needed. Finally, a coordinated EU or ESA education and outreach program would improve the participation of the public in the astrobiological activities.

Extremophile Microalgae: the potential for biotechnological application

“…, Martins et al. ). Studies of life in extreme deserts show that even a small amount of rain, fog, snow, and atmospheric humidity can be adequate for photosynthesis to occur, thus producing a small but detectable microbial community (Mckay ).…”

“…) as well as the field of astrobiology (Chyba and Hand , Martins et al. , Cottin and Rettberg , Joseph et al. ).…”

Overview and perspectives of Astrobiology

“…对地外天体宜居环境的判别主要依据对地球类似 极端环境的类比研究. 截止到2017年, 人们已经发现了 至少37个不同的类比研究地点或环境 [68] , 包括我国柴 达木盆地类火星环境和地貌 [69,70] . 对这些极端环境中 微生物的研究改变了人们对生命生存极限的认识.…”

Mosses in Low Earth Orbit: Implications for the Limits of Life and the Habitability of Mars

“…Dry extreme environments on Earth can be regarded as martian field analogs such as the Antarctic Dry Valleys or hot deserts (Hansen et al, 2007;Martins et al, 2017). Hence, extreme terrestrial habitats are suitable to study the ability of resident organisms to resist extraterrestrial stressors such as ultraviolet radiation (UVR), Mars-like atmosphere, or extreme temperatures (Fairén et al, 2010;Horneck et al, 2010;Martins et al, 2017).…”

“…Dry extreme environments on Earth can be regarded as martian field analogs such as the Antarctic Dry Valleys or hot deserts (Hansen et al, 2007;Martins et al, 2017). Hence, extreme terrestrial habitats are suitable to study the ability of resident organisms to resist extraterrestrial stressors such as ultraviolet radiation (UVR), Mars-like atmosphere, or extreme temperatures (Fairén et al, 2010;Horneck et al, 2010;Martins et al, 2017). A range of organisms have already been investigated in these habitats such as microbial communities collected in permafrost soils (Hansen et al, 2009), endolithic cyanobacteria from deserts (Baqué et al, 2013), or cryptoendolithic fungi from Antarctica Selbmann et al, 2015;Pacelli et al, 2016).…”