From Warm And Wet To Cold And Dry On Mars: Ancient Environments As Seen From A Rover Perspective

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My interest in geology began as a child when I lifted every other pebble on my hometown's beach. Scientific understanding was added to this curiosity with a Geography GCSE, a Geology A Level, a Geology and Petroleum BSc and a Planetary Science MSc. I have loved learning about the Earth's past environments and applying it to other planetary bodies. I have a strong geoscience base with a BSc in Geology and Petroleum Geology, from The University of Aberdeen. This degree taught me how to analyse past environments from geological samples. I then went on to complete an MSc in Planetary Science at University College London. Where I learnt the geological history of other planetary bodies and explored earth-based analogues for them. The recent launch of Mars2020 has inspired andprovoked an academic focus on understanding Mars environment and habitability. I would love to work with the future samples that will be returned by this mission in my later career. Therefore, getting to support NASAs Curiosity and Perseverance missions by determining what environmental conditions were present for water-rock reaction processes at the rover landing sites, especially as wetransition from a warm and wet to a cold and dry Mars.During the above degrees, I tailored my modules and essays to a Martian geology focus. Including a master's thesis titled, The Biwabik Formation as A Microfossil Analogue of Early Mars'. This included laboratory work, a literature review, a research paper, and a presentation. I am about to rewrite these results into a paper for submission to peer-reviewed journals. This project is composed of a mineralogical assessment of thin samples of the Biwabik Formation, a stromatolite-banded iron formation, this rock was used as an analogue for an early Mars shoreline. I recorded several potential biosignatures using optical microscopy, Raman spectroscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy. This allowed me to see many shapes that mirror carbon oxidation reactions such as spotting, botryoids and diffuse gradients. I also recorded organic matter and filamentous shapes, that may have come from fossilised bacteria. This project was preceded by a literature review that covered Martian geology, stromatolites, Biwabik formation geology, fossilised microbes, analytical techniques such as SEM EDS and Raman, carbon oxidation reactions, Martian exploration missions and biosignatures. I would like to continue to develop an expertise in Martian environments, past and present. This project inspires me as it assists with the largest question in science, were we the only habitable planet in our solar system? NASAs Curiosity and Perseverance are still working hard on Mars, examining the rocks as they transitioned from a wet Mars to a dry Mars and evaporation environment at the end of the Amazonian period. I want to contribute to the science that will help us understand and unravel the story of Mars when there may have been life created within lakes, by using thermochemical modelling to determine the environmental conditions that water rock interactionstook place. This life may have left evidence for us, such as altered minerals. I found evidence of similar mineral reactions within a Mars analogue, Biwabik formation stromatolites, during my MSc thesis. One day soon Perseverance Rover will send us back the first ever Martian return samples, extracted from the Jezero Crater. In the meantime, evaluating its biological potential using Earth-basedsimulations will be of great use to prove the findings in the sample. For example, recording secondary alteration minerals that are only produced by biotic processes, detectable by SHERLOC and SuperCam on board Perseverance, as these would be strong biosignatures