The Astrobiology of Archaea

Archaea have two primary roles in thinking about the origin of life: as stowaways in salt inclusions and as possible inhabitants of saline parts of Mars. Thick salt deposits containing living Archaea attest to their durability, perhaps attributable to their polyploidy or salt-protected enzymes. The durations of survival of Archaea in salt inclusions on Earth extend to astronomically plausible times. Three major developments have kept up the hope of detecting life in the Universe beyond our Solar System: The discovery of thousands of exoplanets; the discovery of many protoplanetary disks; and probable Ocean Worlds. While planetary disks are presumed too young to harbor life, possible precursors to life are being detected. The rate of discovery of organic molecules in space is likely to be paralleled for atmospheres of exoplanets and protoplanetary disks.