Biomarkers, Martian analogues and Raman spectroscopy

Porteous, Rory (2019) Biomarkers, Martian analogues and Raman spectroscopy. PhD thesis, University of Glasgow.

Abstract

In the search for signs or traces of extraterrestrial life we are confined to our understanding of how life arose on Earth, processes that are intrinsically tied to our understanding of both the biotic and abiotic process that formed many of the features on this planet. Understanding how life arose on Mars, and where any such signs of life could persist, requires an understanding of the same processes that took place on Earth, in addition to how those signs could have persisted over the timescale in which Mars would have been considered a ‘lifeless’ planet. Exploration of Mars is highly dependent on prioritization of sample sites that maximise the potential for discoveries that justify the expense and difficulty of exploring a planet that is not our own.
This study sought to determine whether a possible origin of life environment could provide data sufficient to encourage targeting such a location for future Mars missions. Hydrothermal vents where heated waters from a volcanically active zone could provide the necessary mineral surfaces, thermal gradient and possible sources of organic molecules from the earth’s crust to form the first proto-cells. Both terrestrial and particularly aquatic hydrothermal vents are the source of energy for many bacteria. In aquatic settings a hydrothermal vent is often the sole source of energy for any potential community. The silica sinters analysed in this thesis returned 3 potential sources of biosignatures; actively viable bacteria that were able to be cultured; visual evidence of microbial encrustation in the form of filamentous or coccal bacteria; and organic biomarkers in the form of n-alkanes, fatty acids and other organic compounds.
It was also established that the Chilean Altiplano could be considered a Martian analogue due to its similar environmental characteristics (temperature, humidity, increased UV, low biomass) and a diurnal soil cycle matching that on Mars with regards to cold atmospheric temperatures and surface heating of soils leading to a fluctuating temperature and soil humidity profile.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Mars, Biomarkers, Raman, Earth Sciences, Silica Sinter, Altiplano, Martian Analogue
• Subjects: G Geography. Anthropology. Recreation > GE Environmental Sciences; Q Science > QD Chemistry; Q Science > QE Geology
• Colleges/Schools: College of Science and Engineering > School of Geographical and Earth Sciences > Earth Sciences
• Supervisor's Name: Toney, Professor Jaime and Lee, Professor Martin
• Date of Award: 2019
• Depositing User: Mr Rory Porteous
• Unique ID: glathesis:2019-73981
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 21 Jun 2019 09:07
• Last Modified: 28 Jun 2022 08:44
• Thesis DOI: 10.5525/gla.thesis.73981
• URI: https://theses.gla.ac.uk/id/eprint/73981