Extremophiles and the Search for Extraterrestrial Life

TLDR

Extremophiles inhabit a wide range of extreme environments—ice, boiling water, acid, salt crystals, and even nuclear reactor cores—spanning all three domains of life and expanding the catalog of potential extraterrestrial habitats. This paper evaluates extremophiles and extreme environments in the context of astrobiology and the search for extraterrestrial life. The study relies on genome sequencing and functional analyses of extremophiles to assess biomarkers, evolutionary insights, and survival capabilities relevant to astrobiology.

Abstract

Extremophiles thrive in ice, boiling water, acid, the water core of nuclear reactors, salt crystals, and toxic waste and in a range of other extreme habitats that were previously thought to be inhospitable for life. Extremophiles include representatives of all three domains (Bacteria, Archaea, and Eucarya); however, the majority are microorganisms, and a high proportion of these are Archaea. Knowledge of extremophile habitats is expanding the number and types of extraterrestrial locations that may be targeted for exploration. In addition, contemporary biological studies are being fueled by the increasing availability of genome sequences and associated functional studies of extremophiles. This is leading to the identification of new biomarkers, an accurate assessment of cellular evolution, insight into the ability of microorganisms to survive in meteorites and during periods of global extinction, and knowledge of how to process and examine environmental samples to detect viable life forms. This paper evaluates extremophiles and extreme environments in the context of astrobiology and the search for extraterrestrial life.