UK Centre for Astrobiology


Meet the group

Principal Investigator: Sean McMahon


I am a palaeobiologist and astrobiologist: a geoscientist interested in the co-evolution of life and planetary environments across very large spans of space and time. As a tenured Chancellor’s Fellow at the University of Edinburgh and co-director (with Charles Cockell and Rosa Santomartino) of the UK Centre for Astrobiology, I focus on the study of biosignatures in ancient materials relevant to the early Earth, Mars, and beyond. My work has been published in a wide range of journals and reported with varying degrees of accuracy by diverse TV, radio, online and printed media. I am a Fellow of the Royal Astronomical Society and of the Geological Society of London, a member of the Palaeontological Association and the Astrobiology Society of Britain, and an Associate Editor of the International Journal of Astrobiology, published by Cambridge University Press. I am also a STEM Ambassador.

Background: I studied for an MEarthSci (Earth Sciences) at St Edmund Hall, University of Oxford (2006–2010) and developed an interest in early life and astrobiology under the tutelage of the late Martin Brasier (and, briefly, Lynn Margulis). This interest led me to the University of Aberdeen for my STFC-funded doctoral research (2010–2014) on the habitability of subsurface environments on Earth and Mars (supervisors: John Parnell, Gail Ferguson, and Graeme Nicol). I also undertook a NASA Planetary Biology Internship in the laboratory of Rocco Mancinelli at NASA Ames Research Center in California. After my PhD, I joined Derek Briggs' lab at Yale University for postdoctoral research on fossilization processes (2014-2017) funded by the NASA Astrobiology Institute, before returning to Scotland as a Marie Skłodowska-Curie Fellow at Edinburgh's UK Centre for Astrobiology (2017-2019). Except for a brief visit to Durham University as a visiting fellow at the Institute for Advanced Study, I have remained in Edinburgh since 2019 as a Chancellor's Fellow in Astrobiology and received tenure (i.e., a permanent position) in 2022. I also hold a BA in Philosophy from Birkbeck College, University of London.


Postdoctoral scientists

Corentin Loron, Royal Society Newton International Fellow


Corentin Loron (BSc Lille 1, MSc Uppsala-Lille-1, PhD Liège) is investigating the oldest fossil fungi and their pathways of fossilization.


PhD students (co-supervised)

Philippe Reekie (University of Edinburgh)


Lead supervisor: Charles Cockell

Philippe Reekie (BSc Birkbeck, MScR Edinburgh) is researching perchlorate glasses, mineral veins and the search for extraterrestrial life.

Sigrid Huld (Uppsala University)


Lead supervisor: Anna Neubeck

Sigrid (BSc Pavia, MSc Uppsala) is researching the biogeochemistry of manganese and the production of self-organized pseudofossils on early Earth and Mars.


MScR students

Melanie Podbielski (MScR Palaeontology and Geobiology)


Melanie (BS Appalachian State University) is investigating the fossilization of iron-oxidizing bacteria.



Susie Seddon-Cowell (MScR Palaeontology and Geobiology)


Susie (BSc University of York) is investigating the fossilization of bacteria under extreme conditions.

Edwin Rodriguez Dzul (MScR Palaeontology and Geobiology)

Edwin (BSc Autonomous University of Yucatan) is researching the morphological and molecular preservation of fossil microbes in the ~407-million-year-old Rhynie Chert, Scotland.


Notable former students

Elisha de Mello (Physics MPhys project student, 2019)

Elisha completed an MPhys research project entitled, "Hydrodynamic Forcing of Stromatolite Morphology" based on numerical modeling of the growth of organosedimentary structures. Elisha is now a PhD student at the University of Sheffield.

Sam Johnson (Theoretical Physics BSc project student, 2020)


Sam completed a Senior Honours Project entitled, "Numerical approaches to self-organization in agates" based on the numerical modeling of diffusive and layered growth structures in agates. Sam then moved to Gonville and Caius College, Cambridge to complete the MASt in Applied Mathematics (Part III of the Mathematical Tripos).


 Lab mascot



Violet is researching the possible existence of squirrels in that tree. She is not allowed in the laboratories.


Long-term external collaborators

  Prof Joel de Witt, East Carolina University (collaborator on radiation physics)
  Dr Ashleigh Hood, Melbourne University (collaborator on geochemistry, geobiology)
  Dr Magnus Ivarsson, National Museum of Natural History, Stockholm (collaborator on the fossil record of subsurface life)
  Prof Alex Liu, University of Cambridge (collaborator on taphonomy, Ediacaran palaeobiology)
  Dr Jack Matthews, Oxford University Museum of Natural History (collaborator on Ediacaran palaeobiology, exogeoconservation)
  Prof Anna Neubeck, University of Uppsala (collaborator on the origin of life, pseudofossils)
  Prof John Parnell, University of Aberdeen (collaborator on the geology of the deep biosphere)

Prof Oliver Steinbock, Florida State University (collaborator on pseudofossils, biomorphs)

  Dr Peter Vickers, Durham University (collaborator on the philosophy of astrobiology)