UK Centre for Astrobiology


Published articles and chapters


53. Toward sustainable space exploration: a roadmap for harnessing the power of microorganisms. Santomartino, R., Averesch, N.J., Bhuiyan, M., Cockell, C.S., Colangelo, J., Gumulya, Y., Lehner, B., Lopez-Ayala, I., McMahon, S., Mohanty, A. and Santa Maria, S.R., Nature Communications, 14, 1391.

52. Molecular fingerprints resolve affinities of Rhynie chert organic fossils. Loron, C.C.Rodriguez Dzul, E., Orr, P.J., Gromov, A.V., Fraser, N.C., McMahon, S. Nature Communications 14, 1387



51. Chemical gardens mimic electron paramagnetic resonance (EPR) spectra and morphology of biogenic Mn oxides. Huld, S., McMahon, S., Sjoberg, S., Huang, P. & Neubeck, A. Astrobiology.

50. Petrified Chemical Gardens. Knoll, P., Bastita, B., McMahon, S., & Steinbock, O. ACS Earth and Space.

49. The Effect of Grain Size on Porewater Radiolysis. deWitt, J., McMahon, S., & Parnell, J. Earth and Space Science.

48. A fundamental limit to the search for the oldest fossils. McMahon, S., & Jordan, S.F. Nature Ecology and Evolution



47. False biosignatures on Mars: Anticipating Ambiguity. McMahon, S., & Cosmidis, J. Journal of the Geological Society.

46. Late Ediacaran life on land: desiccated microbial mats and large biofilm streamers. McMahon, S., Matthews, J.J., Brasier, A., Still, J. Proceedings of the Royal Society B.

45. Estimating Microbial Hydrogen Consumption in Hydrogen Storage in Porous Media as a Basis for Site Selection. Thaysen, E., McMahon, S., Strobel, G., Butler, I., Ngwenya, B., Heimemann, N., Wilkinson, M., Hassanpouryouzband, A., McDermott, C., and Edlmann, K. Renewable and Sustainable Energy Reviews

44. Astrobiology (Overview). McMahon, S. Oxford Research Encyclopedia of Planetary Science.

43. Dubiofossils from a Mars‐analogue subsurface palaeoenvironment: The limits of biogenicity criteria. McMahon, S., Ivarsson, M., Wacey, D., Saunders, M., Belivanova, V., Muirhead, D., Knoll, P., Steinbock, O. and Frost, D.A. Geobiology (available online).

42. Ediacaran metazoan reveals lophotrochozoan affinity and deepens root of Cambrian Explosion. Shore, A. J., Wood, R. A., Butler, I. B., Zhuravlev, A. Yu., McMahon, S., Curtis, A., & Bowyer, F. T. Science Advances 7, eabf2933.



41. When is Life a Viable Hypothesis?:The Case of Venusian Phosphine. Cockell, C. S., McMahon, S., & Biddle, J. F. Astrobiology (available online).

40. Determination of the microscopic mineralogy of inclusion in an amygdaloidal pillow basalt by fs-LIMS. Tulej, M., Lukmanov, R., Grimaudo, V., Riedo, A., Koning, C., Ligterink, N. F. W., Neubeck, A., Ivarsson, M., McMahon, S. & Wurz, P. Journal of Analytical Atomic Spectroscopy (available online).

39. Mars-Analog Calcium Sulfate Veins Record Evidence of Ancient Subsurface Life. McMahon, S., Parnell, J. & Reekie, P. B. R. Astrobiology 20 (available online).

38. 0.25 Ga salt deposits preserve signatures of habitable conditions and ancient lipids. Cockell, C. S., Wilhelm, M. B. Scott, P., Wadsworth, K., Payler, S., McMahon, S., Paling, S., & Edwards, T.  Astrobiology 20, 864–877.

37. Do Extraordinary Claims Require Extraordinary Evidence? The Proper Role of Sagan’s Dictum in Astrobiology. McMahon, S. In: Smith, K.C., & Mariscal, C. (Eds.), Social and Conceptual Issues in Astrobiology. Oxford University Press, New York.



36. Earth’s earliest and deepest purported fossils may be iron-mineralized chemical gardens. McMahon, S. Proceedings of the Royal Society B: Biological Sciences 286, 20192410.

35. A laboratory for multi-century science. Cockell, C.S., Santomartino, R., McMahon, S., Reekie, P., Alberti, S.J.M.M., Phillipson, T., Russell, S. In: Astronomy & Geophysics 60, 6.26–6.28

34. Sample Collection and Return from Mars: Optimising Sample Collection Based on the Microbial Ecology of Terrestrial Volcanic Environments. Cockell, C.S., McMahon, S., Lim., D.S.S., Rummel, J., Stevens, A.H., et al. Space Science Reviews 215: 44.

33. Forum Reply: Petrological evidence in support of the death mask model for Ediacaran soft-bodied preservation in South Australia. Liu, A.G., McMahon, S., Matthews, J.J., Still, J., Brasier, A.T., & Marosi, D.M. Geology 47, e474.

32. Lifeless Martian samples and their significance. Cockell, C.S., McMahon, S. Nature Astronomy 3, 468-470.

31. A new frontier for palaeobiology: Earth’s vast deep biosphere. McMahon, S., & Ivarsson, M. BioEssays 41, 1900052.

30. Petrological evidence in support of the death mask model for Ediacaran soft-bodied preservation in South AustraliaLiu, A.G., McMahon, S., Matthews, J.J., Still, J., & Brasier, A.T. Geology 47, 215-218.



29. Reduction spheroids preserve a uranium isotope record of the ancient deep continental biosphereMcMahon, S., Hood, A. vS., Parnell, J., & Bowden, S. Nature Communications 9, 4505.

28. The deep history of Earth’s biomassMcMahon, S., & Parnell, J. Journal of the Geological Society 175, 716–720.

27. Exogeoconservation: Protecting geological heritage on celestial bodies. Matthews, J. J., & McMahon, S. Acta Astronautica 149, 55–60.

26. A field guide to finding fossils on MarsMcMahon, S., Bosak, T., Grotzinger, J.P., Milliken, R. E., Summons, R. E., Daye, M., Newman, S. A., Fraeman, A., Williford, K.H ., & Briggs, D. E. G.  Journal of Geophysical Research: Planets 123, 1012–1040. Top 20 most downloaded article in JGR: Planets, 2017–2018

25. Palaeobiology of latest Ediacaran phosphorites from the upper Khesen Fm., Khuvsgul Gp., northern Mongolia. Anderson, R. P., McMahon, S., Macdonald, F. A., Jones, D. S., & Briggs, D. E. G. Journal of Systematic Palaeontology.

24. Demonstrating deep biosphere activity in the geological record of lake sediments, on Earth and Mars. Parnell, J., McMahon, S., & Boyce, A. International Journal of Astrobiology 17, 380–385.



23. Doushantuo-type microfossils from latest Ediacaran phosphorites of northern Mongolia. Anderson, R. P., Macdonald, F. A., Jones, D. S., McMahon, S., & Briggs, D. E. G. Geology 45, 1079–1082.

22. Biofilms mediate the preservation of leaf adpression fossils by clays. Locatelli, E., McMahon, S., & Bilger, H. Palaios 32, 708–724. Palaios Outstanding Paper of 2017.

21. Decay of the sea anemone Metridium (Actiniaria): Implications for the preservation of soft-bodied diploblast-grade animals. McMahon, S., Tarhan, L. G., & Briggs, D. E. G. Palaios 32, 388–395.

20. Palaeobiology of the early Ediacaran Shuurgat Formation, Zavkhan Terrane, southwestern MongoliaAnderson, R. P., McMahon, S., Bold, U., Macdonald, F. A., & Briggs, D. E. G. Journal of Systematic Palaeontology 15, 947–968.

19. The Origin and Occurrence of Subaqueous Sedimentary Cracks. McMahon, S., Hood, A. v S., & McIlroy, D. Geological Society of London, Special Publications 448, 285–309.



18. The aesthetic objection to terraforming MarsMcMahon, S. In: Schwartz, J.S.J., & Milligan, T. (Eds.), The Ethics of Space Exploration. Springer, London.

17. Evidence for seismogenic hydrogen gas, a potential microbial energy source on Earth and MarsMcMahon, S., Parnell, J., & Blamey, N. J. Astrobiology 16, 690–702.

16. Experimental evidence for inhibition of bacterial growth by clay minerals and its implications for fossil preservationMcMahon, S., Anderson, R. P., Saupe, E. E., & Briggs, D. E. G. Geology 44, 867–870.

15. The Tully Monster is a Vertebrate. McCoy, V. E., Saupe, E. E., Lamsdell, J. C., Tarhan, L. G., McMahon, S., Lidgard, S., Mayer, P., Whalen, C. D., Soriano, C., Finney, L., Vogt, S., Clark, E. G., Anderson, R. O., Petermann, H., Locatelli, E. R., & Briggs, D. E. G. Nature 532, 496–499.

14. Mineralogical determination in situ of a highly heterogeneous material using a miniaturized laser ablation mass spectrometer with high spatial resolutionNeubeck, A., Tulej, M., Ivarsson, M., Broman, C., Riedo, A., McMahon, S., Wurz, P., & Bengston, S. (2016) . International Journal of Astrobiology 15, 133–146.

13. The role of experiments in investigating the taphonomy of exceptional preservationBriggs, D.E.G., & McMahon, S. Palaeontology 59, 1–11.

12. Physical and Chemical Controls on Habitats for Life in the Deep Subsurface Beneath Continents and Ice. Parnell, J., McMahon, S. Transactions of the Royal Society of London A 374, 20140293.



11. Martin Brasier (1947-2014): Astrobiologist. McMahon, S., Cockell, C. S. International Journal of Astrobiology 14, 527–531.

10. Evidence for methane in martian meteorites.Blamey, N., Parnell, J., McMahon, S., Mark, D., Tomksinson, T., Lee, M., Shivak, J., Izawa, M., Banerjee, N., & Flemming, R. Nature Communications 6: 7399.



9. Parnell, J., McMahon, S., Blamey, N. J. F., Hutchinson, I. B., Harris, L. V., Ingley, R., Edwards, H. G. M., Lynch, E. & Feely, M. Detection of reduced carbon in a basalt analogue for martian nakhlite: a signpost to a habitat on Mars. International Journal of Astrobiology 13: 124-131.

8. Price, M., Ramkissoon, N., McMahon, S., Miljkovic, K., Parnell, J., Wozniakiewicz, P., Kearsley, A., Blamey, N., Cole, M., & Burchell, M. Limits on methane release and generation via hypervelocity impact of Martian analog materials. International Journal of Astrobiology 13: 132-140.

7. McMahon, S., Parnell, J. Weighing the deep continental biosphere. FEMS Microbiology Ecology 87: 113-120. Chief Editor’s Choice, January 2014.



6. McMahon, S., O’Malley-James, J., & Parnell, J. Circumstellar habitable zones for terrestrial deep biospheres. Planetary and Space Science 85, 312–318.

5. McMahon, S., Parnell, J., Ponicka, J., Hole, M., & Boyce, A. The habitability of vesicles in martian basalt. Astronomy & Geophysics 54, 1.17–1.21.

4. Brasier, M., Matthewman, R., McMahon, S., Kilburn, M., & Wacey, D. Pumice from the ~3,460 Ma Apex Basalt, Western Australia: a natural laboratory for the early biosphere. Precambrian Research 224, 1–10.

3.Sampling methane in basalt on Earth and Mars. McMahon, S., Parnell, J., & Blamey, N. J. F.  International Journal of Astrobiology  12, 113-122.



2. McMahon, S., Parnell, J., & Blamey, N. J. F. Sampling methane in hydrothermal minerals on Earth and Mars. International Journal of Astrobiology 11, 163-167.



1. Brasier, M.D.,  Matthewman, R., McMahon, S., & Wacey, D. Pumice as a Remarkable Substrate for the Origin of Life. Astrobiology 11, 725-735.