Detecting life on Mars through the study of organic host Mars analogues and Urey instrument development
Author(s)
Marlow, Jeffrey
Type
Thesis
Abstract
The search for life on Mars is one of today’s most exciting and far-reaching scientific
challenges. The European Space Agency’s ExoMars mission will renew the pursuit of signs of past or
present life equipped with a range of analytical instruments: one such instrument will likely be Urey, a
tool that will extract and analyze organic molecules. This thesis first seeks to contextualize the search
for life through the use of analogue sites on Earth and ultimately works to optimize the
spectrofluorometric detection of relevant organic molecules.
Organic host analogues – sites on Earth where life faces similar challenges as potential martian
life forms – aid in mission planning and data analysis. With these dual purposes in mind and the
understanding that collaborative analogue use benefits all stakeholders, the Imperial College Mars
Analogue Repository (ICMAR) was established. Samples from Iceland and the Middle Atlas
mountains of Morocco were gathered to start the collection. As it grows, mission planners and
scientists will have a centralized, well-characterized set of samples for astrobiological studies.
Optimizing Urey’s spectrofluorometric detection of amino acids and polycyclic aromatic
hydrocarbons (PAHs) was another primary aim of this study. Standard solutions were tested across a
range of instrumental parameters and an ideal excitation wavelength was identified to optimize the
detection of any organics present at the sampling site. The fluorescent interaction between molecules
was also investigated to evaluate the instrument’s ability to detect and quantify complicated, multicomponent
samples. Finally, natural organic-rich samples from England’s Blue Lias formation were
tested to evaluate spectrofluorometric analysis of natural samples – a capability that will be crucial for
in situ martian analysis.
By highlighting the role of organic Mars analogues and optimizing the Urey instrument, this
thesis enhances ExoMars’ ability to identify organic molecules and sets the stage for continued martian
exploration.
challenges. The European Space Agency’s ExoMars mission will renew the pursuit of signs of past or
present life equipped with a range of analytical instruments: one such instrument will likely be Urey, a
tool that will extract and analyze organic molecules. This thesis first seeks to contextualize the search
for life through the use of analogue sites on Earth and ultimately works to optimize the
spectrofluorometric detection of relevant organic molecules.
Organic host analogues – sites on Earth where life faces similar challenges as potential martian
life forms – aid in mission planning and data analysis. With these dual purposes in mind and the
understanding that collaborative analogue use benefits all stakeholders, the Imperial College Mars
Analogue Repository (ICMAR) was established. Samples from Iceland and the Middle Atlas
mountains of Morocco were gathered to start the collection. As it grows, mission planners and
scientists will have a centralized, well-characterized set of samples for astrobiological studies.
Optimizing Urey’s spectrofluorometric detection of amino acids and polycyclic aromatic
hydrocarbons (PAHs) was another primary aim of this study. Standard solutions were tested across a
range of instrumental parameters and an ideal excitation wavelength was identified to optimize the
detection of any organics present at the sampling site. The fluorescent interaction between molecules
was also investigated to evaluate the instrument’s ability to detect and quantify complicated, multicomponent
samples. Finally, natural organic-rich samples from England’s Blue Lias formation were
tested to evaluate spectrofluorometric analysis of natural samples – a capability that will be crucial for
in situ martian analysis.
By highlighting the role of organic Mars analogues and optimizing the Urey instrument, this
thesis enhances ExoMars’ ability to identify organic molecules and sets the stage for continued martian
exploration.
Date Issued
2010
Date Awarded
2010-09
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Sephton, Mark
Sponsor
Marshall Scholarship Programme ; Science and Technology Facilities Council
Creator
Marlow, Jeffrey
Publisher Department
Earth Science and Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Master of Philosophy (MPhil)