Abstract

Documentation of primitive terrestrial life signatures and the methods used to characterize them will be relevant to identify signatures of biological origin at the surface of Mars. In this respect, fossils of chemolithotrophic microorganisms found in ancient volcanic rocks on Earth are used as analogues for the kinds of microorganisms that could be found on Mars. Indeed, chemolithotrophs are the ancient forms of life thought to inhabit the first habitats on Earth and potentially on Mars when the two planets had similar conditions in their early history, i.e. an atmosphere, geological activity and enough liquid water in specific habitable localities for a prolonged period of time.