Multiple projects funded for Mars exploration research

Dr Claire Cousins from the Department of Earth and Environmental Sciences (DEES) was recently awarded four research projects, totalling a value of £422K, funded by the UK Space Agency as part of their ongoing ‘Aurora’ programme and The Leverhulme Trust. All these projects relate to the exploration of Mars, spanning both fundamental research and technology development.

The 3.5 year UK Space Agency PhD Studentship “Chemolithotrophs on Mars: metabolic pathways and biosignatures” will explore the metabolisms and stable isotope fractionation patterns produced by microbial communities in Mars analogue environments, and will be co-supervised by Dr Aubrey Zerkle. This will help us understand what kind of evidence we might expect to be left by any microbial life that existed billions of years ago when Mars was a less hostile planet.

Complementing this studentship is a 3-year postdoctoral project that will explore the habitability of hydrothermal fluids on Mars, Europa and Enceladus (“Frozen but not forgotten: microbial habitability and preservation in planetary fluids”; The Leverhulme Trust). This project will combine natural mineral springs in the Canadian High Arctic and Iceland with experimental studies to investigate how microbial communities survive and are preserved in simulated planetary environments. Dr Gordon Osinksi from the University of Western Ontario who visited DEES during his sabbatical in April 2016 is a Co-Investigator on this project, along with Dr Mark Claire (DEES) and Prof Charles Cockell (University of Edinburgh).

Testing the ExoMars PanCam in Iceland in 2013 

Finally, a 2-year proof-of-concept UK Space Agency project, led by Dr Matthew Gunn at Aberystwyth University, will develop a prototype instrument to conduct “Luminescence age dating for in situ environments” on Mars. Luminescence age dating is widely used in environmental sciences, but has yet to be used in the robotic exploration of Mars. Creating new instrument prototypes means they can be developed into more advanced instruments for missions to the Martian surface in the future. 

Links to related research:

Selecting the geology filter wavelengths for the ExoMars Panoramic Camera Instrument, Cousins, C. R., et al., 2012, In: Planetary and Space Science.

Mars surface context cameras past, present, and future, Cousins, C. R., et al., 27 April 2016, In: Earth and Space Science.

Glaciovolcanic hydrothermal environments in Iceland and implications for their detection on Mars, Cousins, C. R., et al., Cousins, C. R., et al., 15 Apr 2013, In: Journal of Volcanology and Geothermal Research. 256, p. 61-77.

Volcano-Ice Interaction as a Microbial Habitat on Earth and Mars, Claire R. Cousins and Ian A. Crawford. Astrobiology. September 2011, 11(7): 695-710.

Related media stories:

New Scientist: ExoMars rover's Martian-hunting camera takes test run in Iceland
Imperative Space: Aurora and ExoMars Films for UK Space Agency
The Leverhulme Trust:  Looking for life in the UV: fluorescence as a tool for planetary exploration

Two billion year old microbial ecosystems

Phosphorus is a key element for life---as phosphate (PO4) it helps form the structural framework of information storing DNA and RNA, and has crucial functions in the energy and support systems of organisms (such as ATP). Phosphorous occurs naturally in a number of minerals (e.g. apatite, which is calcium phosphate) and is even present in meteorites, but it is via a variety of weathering and microbial mechanisms that phosphorous-rich deposits (phosphorites) are formed. To do so microbially requires a bacterial consortium, an ecosystem driven by various microbes generating a complementary suite of reduction-oxidation processes specific to the organic and electron-donor substrates in a particular environmental setting.

Fig. 1. Fossilised sulphur-oxidising bacteria preserved
in 2 billion year old rocks, Karelia NW Russia (photo:
Aivo Lepland, Norwegian Geological Survey).

This is where Dr Tony Prave in the Department of Earth and Environmental Sciences and his colleagues have contributed to understanding the linkages between the processes associated with the biologically mediated phosphorous cycle and the formation of the earliest global phosphorites. The international team of geologists and biogeochemists, led by Dr Aivo Lepland of the Norwegian Geological Survey, focussed their efforts on rocks found in Karelia, NW Russia. These rocks are two billion years old and the unit of interest is the Zaonega Formation, a succession of organic-rich rocks containing phosphorite beds that was deposited during a period in Earth history when free di-oxygen was becoming abundant in the atmosphere and shallow portions of the oceans (the 2.3 billion year old event termed the Great Oxidation Event).

Cylindrical apatite particles indicative of a biogenic
origin and typically attributed to methanotrophic archaea
(photo: Aivo Lepland, Norwegian Geological Survey).

What Tony and co-workers documented within Karelian phosphorites is the presence of a fossilised microbial consortium, which in their interpretation consisted of sulphur bacteria (Fig. 1) associated with a fabric of cylinders composed of the phosphate-bearing mineral apatite (Fig. 2). The consistent size and shape of the apatite crystals is identical to those formed by methanotrophic archaea that in modern microbial ecosystems co-occur commonly with sulphur oxidisers. In effect, the team documented the establishment of a microbial ecosystem similar to those found in modern marine settings in which sulphur-oxidisers and methanotrophs co-habit---the remarkable aspect is that this ecosystem is more than two billion years old. Such geochemical and biological fingerprints provide a key example to constrain and understand the conditions under which life evolved not only on Earth but also potentially on other planets.

Potential influence of sulphur bacteria on Palaeoproterozoic phosphogenesis, Nature Geoscience