Imperial College London


Faculty of EngineeringDepartment of Earth Science & Engineering

Professor of Organic Geochemistry



+44 (0)20 7594 6542m.a.sephton Website




2.34Royal School of MinesSouth Kensington Campus






Organic Geochemistry involves the recognition and interpretation of organic records in planetary settings. Organic structures and their stable isotopic compositions can record chemical evolution in the solar system, the origin of life, habitation of environments and biological evolution over time. Organic compounds are also very sensitive to alteration and post formation changes can be related to thermal, aqueous, radiative and oxidative processing. From  prebiotic chemistry in meteorites, through the many reservoirs of organic molecular fossils on Earth, to the search for evidence of past or present life on Mars, information-rich organic chronicles can be read using modern analytical methods.


  • Professor, Imperial College London 2007 – present
  • Head of Department, Earth Science & Engineering 2016 – 2021
  • Director of Imperial Space Lab, Imperial College London 2015 - 2016
  • Reader, Imperial College London 2005 – 2007
  • Lecturer, Open University 2000 – 2005
  • Post Doc, Open University 1998 – 2000
  • Post Doc, Netherlands Institute for Sea Research (NIOZ) and University of Utrecht 1996 – 1998
  • PhD, Open University 1993 – 1996
  • MSc, University of Newcastle 1991– 1992
  • BSc, University of Durham 1988 – 1991

Research Interests

  • Missions to Mars
  • Mars Analogue Studies
  • Astrobiology of Icy Moons
  • Planetary Protection
  • Meteorites and their Organic Matter
  • Space Spin-Offs
  • Causes and Consequences of Mass Extinctions
  • Organic Proxies of Environmental Change
  • Organic Molecules in Forensic Science and Biochemistry

Notable Outreach Activities

Notable Community Activities

  • 2024 - Member, UK Space Agency Planetary Protection Advisory Panel
  • 2023 - Member, Mars Sample Return Sample Safety Assessment Protocol Tiger Team 
  • 2023 - Member, Mars Sample Return Planetary Protection Re-entry Safety Review Panel
  • 2023 - Member, ESE Programme Board, UK Space Agency
  • 2022 - Member, Royal Society Working Group, Perspective on Space
  • 2022 - Co-Chair Mars Sample Return Temperature and Time Tiger Team
  • 2021 - Speciality Chief Editor for Space Exploration | Frontiers in Space Technologies
  • 2020 - Selected as Returned Sample Science Participating Scientist NASA Mars 2020
  • 2019 - Member of COSPAR Sample Safety Assessment Protocol Working Group
  • 2016 - Team Coordinator for Planetary Protection of Outer Solar System
  • 2015 - Member NASA Mars 2020 Returned Sample Science Board
  • 2014 - Winner of Student Academic Choice Award for Best Supervision
  • 2014 - Member of ESA Planetary Protection Working Group
  • 2013 - Chair of UK Space Agency Space Exploration Advisory Committee
  • 2013 - Member of NASA Science Definition Team for the 2020 Mars Rover
  • 2011 - Member of STFC Astronomy Grants Panel
  • 2010 - Co-Chair of NASA/ESA Mars Sample Return End 2 End International Science Analysis Group

Management and Administration

  • 2021 - 2023 Chair of Targeted Scholarships Sub-Group, Imperial College
  • 2021 - 2023 Societal Engagement Champion, Earth Science & Engineering
  • 2016 - 2021 Head of Department, Earth Science & Engineering
  • 2015 - 2016 Director of Imperial Space Lab, Imperial College
  • 2011 - 2016 Chair of the Department Promotions Panel, Earth Science & Engineering
  • 2010 - 2015 Head of Section, Earth & Planets, Earth Science & Engineering
  • 2005 - 2010 Director of Postgraduate Studies, Earth Science & Engineering
  • 2009 - 2021 Chair of the Department Safety Committee, Earth Science & Engineering
  • 2009 - Present Department Safety Officer, Earth Science & Engineering
  • 2005 - Present Group Leader, Imperial College Organic Geochemistry group

Selected Publications

Journal Articles

Simon JI, Hickman‐Lewis K, Cohen BA, et al., 2023, Samples collected from the floor of Jezero crater with the Mars 2020 Perseverance rover, Journal of Geophysical Research: Planets, Vol:128, ISSN:2169-9097, Pages:1-42

Vaughan A, Minitti ME, Cardarelli EL, et al., 2023, Regolith of the crater floor units, Jezero crater, Mars: textures, composition, and implications for provenance, Journal of Geophysical Research: Planets, Vol:128, ISSN:2169-9097, Pages:1-32

Sephton M, Chan Q, Watson J, et al., 2023, Insoluble macromolecular organic matter in the Winchcombe meteorite, Meteoritics & Planetary Science, ISSN:1086-9379

Royle S, Cropper L, Watson J, et al., 2023, Solid phase micro extraction for organic contamination control throughout assembly and operational phases of space missions, Astrobiology, Vol:23, ISSN:1531-1074, Pages:127-143

Kumar P, Zavala-Reyes JC, Kalaiarasan G, et al., 2023, Characteristics of fine and ultrafine aerosols in the London underground., Science of the Total Environment, Vol:858, ISSN:0048-9697

Chan QHS, Watson JS, Sephton MA, et al., 2023, The amino acid and polycyclic aromatic hydrocarbon compositions of the promptly recovered CM2 Winchcombe carbonaceous chondrite, Meteoritics & Planetary Science, ISSN:1086-9379

Scheller EL, Hollis JR, Cardarelli EL, et al., 2022, Aqueous alteration processes in Jezero crater, Mars-implications for organic geochemistry, Science, Vol:378, ISSN:0036-8075, Pages:1105-1110

King AJ, Daly L, Rowe J, et al., 2022, The Winchcombe meteorite, a unique and pristine witness from the outer solar system., Science Advances, Vol:8, ISSN:2375-2548

Salter TL, Watson J, Waite JH, et al., 2022, Hydrothermal processing of microorganisms: Mass spectral signals of degraded biosignatures for life detection on icy moons, Acs Earth and Space Chemistry, Vol:6, ISSN:2472-3452, Pages:2508-2518

Farley KA, Stack KM, Shuster DL, et al., 2022, Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars, Science, Vol:377, ISSN:0036-8075

Schubotz F, Sephton MA, Derenne S, 2022, Biomarkers in Extreme Environments on Earth and the Search for Extraterrestrial Life in Our Solar System, Elements, Vol:18, ISSN:1811-5209, Pages:100-106

Salter TL, Magee BA, Waite JH, et al., 2022, Mass spectrometric fingerprints of Bacteria and Archaea for life detection on icy moons, Astrobiology, Vol:22, ISSN:1531-1074, Pages:143-157

Potiszil C, Montgomery W, Sephton M, 2021, Heterogeneity within refractory organic matter from CM2 carbonaceous chondrites: evidence from Raman spectroscopy, Earth and Planetary Science Letters, Vol:574, ISSN:0012-821X, Pages:1-10

Tan JSW, Sephton MA, 2021, Quantifying preservation potential: lipid degradation in a Mars-analog circumneutral iron deposit, Astrobiology, Vol:21, ISSN:1531-1074, Pages:1-17

Tan J, Royle S, Sephton M, 2021, Artificial maturation of iron- and sulfur-rich Mars analogues: Implications for the diagenetic stability of biopolymers and their detection with pyrolysis gas chromatography–mass spectrometry, Astrobiology, Vol:21, ISSN:1531-1074, Pages:199-218

Tan J, Sephton M, 2020, Organic records of early life on Mars: the role of iron, burial and kinetics on preservation, Astrobiology, Vol:20, ISSN:1531-1074, Pages:53-72

Royle S, Watson J, Zhang Y, et al., 2019, Solid Phase Micro Extraction: Potential for Organic Contamination Control for Planetary Protection of Life-Detection Missions to the Icy Moons of the Outer Solar System, Astrobiology, Vol:19, ISSN:1531-1074, Pages:1153-1166

Kminek G, Fellous J-L, Rettburg P, et al., 2019, The international planetary protection handbook, Space Research Today, Vol:205, ISSN:1752-9298, Pages:e1-e120

Montgomery W, Jaramillo EA, Royle S, et al., 2019, Effects of oxygen-containing salts on the detection of organic biomarkers on Mars and in terrestrial analogue soils, Astrobiology, Vol:19, ISSN:1531-1074, Pages:711-721

Beaty DW, Grady MM, McSween HY, et al., 2019, The potential science and engineering value of samples delivered to Earth by Mars sample return, Meteoritics & Planetary Science, Vol:54, ISSN:1086-9379, Pages:667-671

Royle SH, Tan J, Kounaves SP, et al., 2018, Survivability of 1-chloronapthalene during simulated early diagenesis – Implications for chlorinated hydrocarbon detection on Mars, Journal of Geophysical Research: Planets, Vol:123, ISSN:2169-9097, Pages:2790-2802

Sephton MA, Waite JH, Brockwell TG, 2018, How to Detect Life on Icy Moons, Astrobiology, Vol:18, ISSN:1531-1074, Pages:843-855

Tan J, Lewis JMT, Sephton MA, 2018, The fate of lipid biosignatures in a Mars-analogue sulfur stream., Scientific Reports, Vol:8, ISSN:2045-2322, Pages:7586-7586

Gordon PR, Sephton MA, 2018, A method for choosing the best samples for Mars sample return, Astrobiology, Vol:18, ISSN:1531-1074, Pages:556-570

Lewis JMT, Najorka J, Watson JS, et al., 2018, The search for Hesperian organic matter on Mars: Pyrolysis studies of sediments rich in sulfur and iron, Astrobiology, Vol:18, ISSN:1531-1074, Pages:454-464

Schulze-Makuch D, Wagner D, Kounaves SP, et al., 2018, Transitory microbial habitat in the hyperarid Atacama Desert, Proceedings of the National Academy of Sciences of the United States of America, Vol:115, ISSN:0027-8424, Pages:2670-2675

Potiszil C, Montgomery W, Sephton MA, 2017, The Effects of Pressure on Model Compounds of Meteorite Organic Matter, Acs Earth and Space Chemistry, Vol:1, ISSN:2472-3452, Pages:475-482

Matthewman R, Crawford IA, Jones AP, et al., 2016, Organic matter responses to radiation under lunar conditions, Astrobiology, Vol:16, ISSN:1557-8070, Pages:900-912

Montgomery WB, Bromiley GB, Sephton MA, 2016, The nature of organic records in impact excavated rocks on Mars, Scientific Reports, Vol:6, ISSN:2045-2322

Montgomery W, Sephton MA, 2016, Pressure effects in polycyclic aromatic nitrogenated heterocycles (PANHs): Diagnostic qualities and cosmobarometry potential, Astrophysical Journal, Vol:819, ISSN:0004-637X

Sephton MA, Carter JN, 2015, The chances of detecting life on Mars, Planetary and Space Science, Vol:112, ISSN:0032-0633, Pages:15-22

Sephton MA, Jiao D, Engel MH, et al., 2015, Terrestrial acidification during the end-Permian biosphere crisis?, Geology, Vol:43, ISSN:1943-2682, Pages:159-162

Lewis JMT, Watson JS, Najorka J, et al., 2015, Sulfate Minerals: A Problem for the Detection of Organic Compounds on Mars?, Astrobiology, Vol:15, ISSN:1557-8070

Montgomery, WB, Sephton MA, et al., 2015, Minimising hydrogen sulphide generation during steam assisted production of heavy oil, Scientific Reports, Vol:5, ISSN:2045-2322

Sephton MA, Lewis JMT, Watson JS, et al., 2014, Perchlorate‐induced combustion of organic matter with variable molecular weights: Implications for Mars missions, Geophysical Research Letters, Vol:41, ISSN:0094-8276, Pages:7453-7460

Sephton MA, Carter JN, 2014, Statistics Provide Guidance for Indigenous Organic Carbon Detection on Mars Missions, Astrobiology, Vol:14, ISSN:1531-1074, Pages:706-713

Montgomery W, Watson JS, Sephton MA, 2014, An organic cosmo-barometer: Distinct pressure and temperature effects for methyl substituted polycyclic aromatic hydrocarbons, Astrophysical Journal, Vol:784, ISSN:0004-637X

Carter JN, Sephton MA, 2013, A Bayesian statistical assessment of representative samples for asteroidal or meteoritical material, Meteoritics & Planetary Science, Vol:48, ISSN:1086-9379, Pages:976-996

Sephton MA, 2013, Aromatic units from the macromolecular material in meteorites: Molecular probes of cosmic environments, Geochimica et Cosmochimica Acta, Vol:107, ISSN:0016-7037, Pages:231-241

Sephton MA, Hazen RM, 2013, On the origins of deep hydrocarbons, Reviews in Mineralogy & Geochemistry, Vol:75, ISSN:1529-6466, Pages:449-465


Sephton MA, 2014, Organic Geochemistry of Meteorites, Treatise on Geochemistry, Editor(s): Turekian, Elsevier Science, Pages:1-31

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