Editorial: Astrobiology at the Interface: Interactions Between Biospheres, Geospheres, Hydrospheres and Atmospheres Under Planetary Conditions

Abstract

Astrobiology is a young, rapidly developing branch of science that seeks to address the question of whether life exists, or has existed, elsewhere in the Universe. It is by nature an interdisciplinary field that explores the origins of life, the conditions and processes that support or challenge life, the influence of different environmental conditions on the preservation and detection of biosignatures of past and present life, and the spread of life across the Universe. As highly interdisciplinary field, astrobiology requires an integrative approach to link the efforts of microbiologists exploring the origins, evolution, and limits of life to the work of geologists exploring both planetary conditions (past and present) and preservation of biosignatures in the geological record. In the search for potential life on other planetary bodies, efforts are being made to combine exoplanet discovery, the study of asteroids and comets, ground-based analyses of recovered meteorites, microbial space exposure experiments with analog planetary-scale biosignature detection. Being a few steps in front of retrieving and returning the first samples from the surface of Mars, we have already gained extensive knowledge from the field, laboratory, and space exposure experiments (McKay and Stoker, [16]; Grotzinger and Milliken, [8]; Westall et al., [25]; Hays et al., [10]). This should enable a comprehensive characterization of the first Mars returned samples in terms of potential exobiology. Outer space, along with ground-based simulating facilities, provides a research tool for studying life in the Universe. Multiple microbial exposure experiments have been successfully performed on board and outside of the International Space Station under the environmental conditions of low Earth orbit (Cockell et al., [4]; Nicholson et al., [19]; Vaishampayan et al., [24]; Kawaguchi et al., [12]; Ott et al., [21]) or mimicking planetary constraints (galactic cosmic and solar UV radiation, temperature fluctuations, microgravity, freezing, desiccation, and extreme vacuum) (Nicholson et al., [19]; Billi et al., [2]; de Vera et al., [5]; Panitz et al., [23]).