Throughout Earth’s geological history, hydrothermal systems have provided habitats for the most ancient forms of life known on Earth. The warm water in these systems reacts with the local rocks and accelerates chemical reactions. As a result, different chemical compounds are released and can be exploited by microorganisms that utilize chemicals from the bedrock for metabolic energy to form a viable habitat.
The geological record of Mars suggests that sulphur-rich hydrothermal systems were widespread during the Hesperian Period, around 3.8 billion years ago and possibly could have supported life as we know it on Earth. This happened shortly after the Late Heavy Bombardment (LHB), when Mars was exposed to extensive impact events. The study of the habitability of these environments is done by researching Mars analogues on Earth. The predominant heat supply of these environments on Earth comes from a magmatic source, either from a volcanic eruption or through a magmatic intrusion into the local rock. On extraterrestrial bodies such as Mars, impacts are the main heat source. The chemical difference between these hydrothermal systems are dependent on the original bedrock and the newly introduced magmatic material. The chemical potential to support microbial life and form a viable habitat between the two different environments will be studied. This will be done by studying relic hydrothermal environments, through analysing rock samples from the sulphur-rich Haughton impact crater in the high Arctic, Canada, and comparing them to magmatic intrusions from the San Raphael Swell, USA. The samples will be collected along a reaction path of unaltered rock to altered rock and analysed for their different mineralogy and chemistry. This will then be used to make a thermodynamic chemical model to understand the reaction path forming the altered rock and the past fluid composition. From the modelled data, the free energy released from the reduction-oxidation reactions will be used to evaluate the different potential of each environment to support microbial life through time and space.