Research proposals 2026-2027

Deposition and chemical interactions between the surface and atmosphere of modern day and ancient Mars

PI: Alexander Archibald, Yusuf Hamied Department of Chemistry
Co-I: Megan Brown, Yusuf Hamied Department of Chemistry

Project summary
In this project the student will develop a mathematical representation of the interactions of key atmospheric gases between Mars’ atmosphere and the surface, looking at key processes such as the uptake and out-gassing of species. They will use present day observations from the ExoMars Trace Gas Orbiter of species such as O3, HCl and CO to evaluate the impact of these interactions of Mars’ atmosphere. The project will then address potential scenarios of Early Mars and how these changes of atmosphere-surface interactions affect our understanding of the stability of Mars’ atmosphere.

Importance of the area of research concerned
Mars is a key analogue in the search for life beyond Earth. An accurate understanding of the atmospheric composition (chemistry) and climate of Mars is therefore crucial. However, despite significant improvement in our knowledge of these processes huge gaps persist. Recent modelling work has identified critical inabilities in state-of-the-art models for simulating the abundance of key species, specifically: O2, H2, CO, HCl, and O3. Recently, detections of ozone from the Perseverance rover imply models are missing surface –atmospheric interactions which could contribute to the deficits between simulations and observations. Failure to accurately model these species hampers our ability to simulate Mars’ atmospheric chemistry-climate system over Mars’ history and so leaves us unable to probe with confidence questions about the habitability of Mars.

What the student will actually do?
The student will work on developing the state-of-the-art 3D global climate model, the Unified Model, and improving the coupled UKCA (the UK Chemistry and Aerosol) model for Mars’ atmosphere. In particular, improving the deposition of nitrogen, hydrogen and oxygen species onto the surface and investigating how the impact from out-gassing from surface geology affects key species. Observations from the Trace Gas Orbiter (TGO; NOMAD and ACS) will provide constraints for the implemented deposition schemes. From these improvements, the student will set up an early Mars scenario and analysis the impact of deposition in an early Mars scenario and quantify the potential impacts these surface-atmosphere interactions may have had on the habitability of ancient Mars.

Requirements as to the educational background of candidates that would be suitable for the project
This project would be particularly suitable for students with backgrounds in the Physical Natural Sciences (Physics or Chemistry), Computational Sciences or Statistics. 

References

D. Viúdez-Moreiras, M.D. Smith, M. Wolff, M.A.J. Brown, F. Daerden, M. Zorzano, V. Apestigue, I. Arruego, E. García, J.J. Jiménez, D. Toledo, M.T. Lemmon, E.W. Knutsen, & A. Saiz-Lopez, Evidence of an enhanced near-surface ozone layer at tropical latitudes on Mars, Proc. Natl. Acad. Sci. U.S.A. 122 (48) e2511744122, https://doi.org/10.1073/pnas.2511744122 (2025).
Lefèvre, F., Trokhimovskiy, A., Fedorova, A., Baggio, L., Lacombe, G., Määttänen, A., et al. (2021). Relationship between the ozone and water vapor columns on Mars as observed by SPICAM and calculated by a global climate model. Journal of Geophysical Research: Planets, 126, e2021JE006838. https://doi.org/10.1029/2021JE006838
Adams D, Luo Y, Wong ML, et al. Nitrogen Fixation at Early Mars. Astrobiology. 2021;21(8):968-980. doi:10.1089/ast.2020.2273

Searching for signs of geological and biological evolution in exoplanetary systems using white dwarfs

PI: Amy Bonsor, Institute of Astronomy

Project summary
Probing exogeology and signatures of biology in planetary material accreted by white dwarfs. Bulk abundances of planetary material seen in the atmospheres of some white dwarfs indicate geological process, including notably core-mantle-crustal differentiation. Key elemental species such as Fe, Ca, Si, Mg indicate the nature of the bodies. Trace species such as Li, Ni, Cr, Mn, P will be used to probe in further detail the evolutionary state of the material. White dwarfs provide the key to interpreting planetary interior models in time for space missions such as PLATO to detect hundreds of rocky exoplanets.

Importance of the area of research concerned
Although complex life clearly exists on Earth, the exact pathway to its existence is yet to be fully understood. Exoplanets provide the perfect opportunity to study what happened in our history that provided a safe haven for life.

Although we now detect many rocky exoplanets, planetary material in the atmospheres of white dwarfs provides a unique means to probe the geological evolution of such planets. Spectroscopy reveals the bulk elemental composition of exoplanets, including Ca, Mg, Fe, P, C, S, Ni, Li etc. White dwarfs provide clear evidence of iron-core and crustal formation.

Spectroscopic follow-up of hundreds of newly identified white dwarfs from Gaia is revolutionizing the field of white dwarf planetary science.

What the student will actually do?
The project is a mixture of spectroscopic data, geochemical and planet formation models. White dwarfs should have pristine spectra, with only features from hydrogen or helium. A small sub-set display many more features. This project is about interpreting these features, using them to infer the composition of the planetary material in the atmosphere of the white dwarf. These compositions are then used, in a similar manner to meteorite data for the Solar System, to interpret the geology and history of the exoplanetary systems.

Requirements as to the educational background of candidates that would be suitable for the project
Strong numerical and computational skills, most likely from a physics, maths or
geosciences background.

References

Bonsor, A., 2024., White Dwarf Systems: the Composition of Exoplanets, Chapter for the 'Encyclopedia of Astrophysics' (Editor-in-Chief Ilya Mandel, Section Editor Dimitri Veras) doi:10.48550/arXiv.2409.13294
Buchan A.~M., Bonsor A., Shorttle O., Wade J., Harrison J., Noack L., Koester D., 2022, Planets or asteroids? A geochemical method to constrain the masses of White Dwarf pollutants, MNRAS, 510, 3512. doi:10.1093/mnras/stab3624
Jura M., Klein B., Xu S., Young E.~D., 2014, A Pilot Search for Evidence of Extrasolar Earthanalog Plate Tectonics, ApJL, 791, L29. doi:10.1088/2041-8205/791/2/L29

PI: Amy Bonsor, Institute of Astronomy
Co-I: Paul Rimmer, Department of Physics

Project summary
This project aims investigates the potential role of delivery to early Earth in origins scenarios.

The project could consider the dynamics of the early Solar System, the physics of impacts onto planetary bodies, the chemistry during impacts or the aftermath of impacts and their relation to prebiotic chemistry.

Importance of the area of research concerned
The tantalising discovery of a wide range of organics on both Ryugu and Bennu, as well as the presence of feedstock molecules, such as HCN, in outer Solar System comets, poses the question of whether delivery to early Earth is a viable pathway for origin of life scenarios.

The early history of our planet was dominated by a period of bombardment, as witnessed by the lunar crater record. Impacts played a potentially crucial role in Earth’s history, with most notably the formation of the Moon itself. This project considers the potential importance of impactors and impact delivery in the origin of life for our planet. Delivery could bring volatiles and potentially prebiotic feedstock molecules to our planet.

What the student will actually do?
The student will work on a range of analytic models, numerical simulations and experimental data, depending on their skill set and strengths. The aim is to build an overall picture of delivery from the dynamics of the early Solar System, through atmospheric entry and hyper-velocity impact onto Earth’s surface. The student will investigate survival during these key steps.

Requirements as to the educational background of candidates that would be suitable for the project
The student would ideally have an aptitude for numerical work, either analytic or computational. Ideal candidates for the project would come from a physics , mathematics or chemistry background.

References

McDonald, C.~H., Bonsor, A., Rae, A.~S.~P., Rimmer, P.~B., Anslow, R.~J., Todd, Z.~R.\ 2025.\ Constraining the survival of HCN during cometary impacts.\ Icarus 441. doi:10.1016/j.icarus.2025.116704
Zellner, N.~E.~B., McCaffrey, V.~P., Butler, J.~H.~E.\ 2020.\ Cometary Glycolaldehyde as a Source of pre-RNA Molecules.\ Astrobiology 20, 1377–1388. doi:10.1089/ast.2020.2216
Sasselov, D.~D., Grotzinger, J.~P., Sutherland, J.~D.\ 2020.\ The origin of life as a planetary phenomenon.\ Science Advances 6, eaax3419. doi:10.1126/sciadv.aax3419

PI: Claudia Bonfio, Department of Biochemistry
Co-I: Edoardo Gianni, MRC LMB

Project summary
The evolution of life likely required early systems to replicate both their genetic material and their compartments. We hypothesise that a primitive cell cycle could emerge if ribozymes were capable of both self-replication and membrane modification. Yet, no study has shown a direct functional link between ribozyme activity and membrane remodelling. By exploring this previously uncharted intersection between primitive membranes and catalytic RNAs, the project will provide insight into one of the most fundamental transitions in the origin of life, by identifying and characterising lipid-modifying ribozymes, and studying their effect on membrane composition, properties and functions.

Importance of the area of research concerned
How did early life evolve the capacity to replicate, divide, and evolve? While modern cells link genotype to phenotype through complex machinery, primitive cells may have established this connection through far simpler means via catalytic RNA (ribozymes) capable of modifying the lipid composition of primitive membranes. This project aims to uncover whether ribozymes can catalyse chemical modifications of primitive lipids and, in doing so, establish a direct genotype-phenotype coupling in primitive cell models. Overall, this project will pave the way towards the emergence of self-modifying primitive cells capable of undergoing growth and division.

What the student will actually do?
This project will develop directed evolution technologies for the identification of lipid-modifying ribozymes, drawing inspiration from known catalytic RNA motifs (e.g., phosphorylating ribozymes).

A generalised in vitro ribozyme selection approach will be implemented to isolate and enrich sequences that induce detectable changes in membrane composition or behaviour. Modulation of membrane features, such as curvature induction and phase separation, will be monitored using light microscopy, fluorescence and Raman spectroscopy. Ultimately, the most promising ribozymes will be tested in tandem with self-replicating ribozymes to investigate the compatibility between ribozyme-driven membrane modification and nucleic acid replication in a primitive cell model.

Requirements as to the educational background of candidates that would be suitable for the project
Due to the nature of the project an undergraduate degree in chemistry or biochemistry is required. The student should have an interest in supramolecular or biophysical chemistry, or artificial cell design and development.

References

Li Y., Horton N. G., O’Flaherty D. K., Rubio-Sanchez R.*, and Bonfio C.* – Beyond charge: hydrophobic features control selective DNA-membrane association. Submitted (2025).
Gianni E., Kwok S. L. Y., Wan C. J. K., Goeij K., Clifton B. E., Attwater J., Holliger P. – A polymerase ribozyme that can synthesize both itself and its complementary strand. bioRxiv (2024). doi: https://doi.org/10.1101/2024.10.11.617851.
Aleksandrova M., Rahmatova F., Russell D. A., Bonfio C.* – Ring-opening of glycerol cyclic phosphates leads to a diverse array of potentially prebiotic phospholipids. JACS (2023), 145, 25614-25620

PI: Claudia Bonfio, Department of Biochemistry
Co-I: Katherine Stott, Department of Biochemistry

Project summary
This project aims at assembling primitive cells capable of division in the absence of modern biochemical machinery.

Our lab has so far focused on the ability of primitive lipids to organise in different lipid domains. We now aim to employ primitive coacervates to modulate the surface area-to-volume of primitive liposomes, ultimately leading to division. This project will provide i) an understanding on the molecular features that govern interactions between membrane-less and membrane-bound compartments, ii) a library of coacervates able to affect the surface area-to-volume of liposomes, and iii) optimised protocols for the spectroscopic characterisation and imaging of primitive cell models.

Importance of the area of research concerned
Throughout evolution, modern cells have developed sophisticated machinery to precisely divide their membrane-bound compartments and regulate them. Yet, the minimal set of cellular components available for primitive cells to drive their division is still unknown. This lack of understanding calls for fundamental studies seeking strategies for primitive cell division.

This project aims to address this knowledge gap by exploring the cooperative interactions between primitive compartments (i.e., membrane-bound and membrane-less compartments), and their impact on enzyme-free cellular division.

Our research will serve as a biochemical platform for probing the origin of cellular replication, and the principles leading to the emergence of living cells.

Moreover, not only will this project explore the synergy between protocell models so far only considered antithetically. It will also offer a more complete picture of the transition from prebiotic chemistry to early life.

What the student will actually do?
The student will be able to develop biophysics and supramolecular chemistry skills, which can be applied to membrane-bound and membrane-less model compartments (i.e., liposomes and biomolecular condensates). Specifically, the student will investigate the compatibility of complex coacervates, made of short oligonucleotides and positively charged peptides, and lipid membranes, composed of primitive lipids (e.g., medium-chain fatty acids, phosphatidic acids and more complex phospholipids). The student will design and develop real-time spectroscopy- and imaging-based protocols to study the interactions between different primitive cell models. The project offers interactions with other groups across multiple departments, including Prof. Lorenzo Di Michele, Dr. Phil Holliger and Prof. Rosana Collepardo-Guevara.

Lu, T.; Liese, S.; Schoenmakers, L.; Weber, C. A.; Suzuki, H.; Huck, W. T. S.; Spruijt, E. Endocytosis of Coacervates into Liposomes. Journal of the American Chemical Society 2022, 144 (30), 13451–13455. https://doi.org/10.1021/jacs.2c04096.
Aleksandrova, M.; Rahmatova, F.; Russell, D. A.; Bonfio, C. Ring Opening of Glycerol Cyclic Phosphates Leads to a Diverse Array of Potentially Prebiotic Phospholipids. J. Am. Chem. Soc. 2023, 145 (47), 25614–25620. https://doi.org/10.1021/jacs.3c07319.
Mihoubi, F. Z.; Nakashima, K. K.; Bonfio, C. Nonenzymatic Autocatalysis Generates Coacervates and Controls Their Structure. Chem 2023, 9 (12), 3394–3396. https://doi.org/10.1016/j.chempr.2023.11.014.

PI: Nicole Shibley, Department of Applied Mathematics & Theoretical Physics, joint with Department of Earth Sciences

Project summary
How does an ice cover affect the habitability of a planet and our ability to infer subsurface processes? In this project, the student will explore planetary habitability, broadly defined, to investigate subsurface ocean dynamics of ice-covered systems.This will include ice-covered moons and early Earth systems. The student will focus on how ice covers, or proxies of them, can be useful in interpreting subsurface ocean dynamics. The ocean dynamics will then be related to signatures of ‘life’.

Importance of the area of research concerned
Many planetary bodies, including Earth, exhibit ice covers overlying subsurface oceans. However, when an ice shell overlies an ocean, inferences of ocean dynamics can be challenging or impossible. The applicability of this concept extends from ice-covered satellites, such as Europa and Enceladus, to ice shells in Earth’s history (i.e., Snowball Earth). The student will build off the existing literature on ice-covered moons to infer ocean dynamics on different satellites, and similarly consider early Earth analogs utilizing what we know from inferences and models. Emphasis will be placed on investigating how ocean stratification and dynamics influence signatures of habitability or life.

What the student will actually do?
Utilize and extend existing physical frameworks (e.g., Shibley et al. 2024; Ashkenazy et al., 2018; Ashkenazy et al., 2013) to infer ocean properties on a variety of ice-covered planetary systems. This will involve mathematical manipulation and theoretical modelling, along with computational analyses. Where it is possible to validate with observations, this will be encouraged.

Requirements as to the educational background of candidates that would be suitable for the project
Strong physics background and maths, computational skills.

References

Shibley, Lai, & Culberg, (2024), How to infer ocean freezing rates on icy satellites from measurements of ice thickness, Monthly Notices of the Royal Astronomical Society, 535(1), 290–298, https://doi.org/10.1093/mnras/stae2304
Ashkenazy, Y., et al. (2013). Dynamics of a Snowball Earth ocean. Nature, 495(7439), 90-93, https://doi.org/10.1038/nature11894.
Ashkenazy, Y., Sayag, R. & Tziperman, E. Dynamics of the global meridional ice flow of Europa’s icy shell. Nat Astron 2, 43–49 (2018). https://doi.org/10.1038/s41550-017-0326-7
Kang, Wanying, et al. "How does salinity shape ocean circulation and ice geometry on Enceladus and other icy satellites?." Science advances 8(29) (2022): eabm4665. https://doi.org/10.1126/sciadv.abm4665

PI: Alex Liu, Department of Earth Sciences, University of Cambridge
Co-I: Dave Lowe, Memorial University of Newfoundland, Canada

Project summary
This project will document the stratigraphic occurrence and paleoenvironmental setting of
individual taxa within the late Ediacaran Catalina Dome. Geological mapping and facies
analysis will permit correlation of individual sections and interpretation of the palaeoenvironments inhabited by organisms. Combining these data with existing geochronological data, we will develop a time-calibrated stratigraphic range chart for taxa in the region, and compare this with other regional and global datasets to develop and test hypotheses regarding evolution and radiation. The project will constrain both the specific depositional settings in which complex animal life evolved, and the timing of evolutionary progress within these ecosystems.

Importance of the area of research concerned
Establishing the timing and trajectory of early animal evolution is vital to efforts to determine the processes responsible for generating Earth’s incredible diversity of animals, and the environmental conditions that nurtured the origination of complex life. Fossils of the Ediacaran macrobiota preserve Earth’s earliest record of large and complex multicellular life, and sites in Newfoundland (Canada) offer some of the oldest fossil assemblages of these organisms. Time-calibrated stratigraphic ranges for Ediacaran taxa in southeastern Newfoundland offer opportunities to develop hypotheses regarding evolutionary trajectories within the Ediacaran biota, but these hypotheses cannot be tested without independent records from other regional and global sites. This project will collect sedimentological and palaeontological data from the Catalina Dome on the Bonavista Peninsula of Newfoundland to document palaeoenvironmental proxies and stratigraphic ranges of taxa there, to ultimately permit distinction between the competing environmental, evolutionary and taphonomic controls on observed fossil distributions of early animals.

What the student will actually do?
You will conduct fieldwork in Newfoundland, Canada, to document petrological, sedimentological and palaeontological data across the Catalina Dome, and to map and correlate individual units and bedding planes in order to construct a coherent stratigraphic column for the region. By incorporating geochronological data from collaborators, you will develop an age model to calibrate your fossil occurrence data, and compare this to existing and novel datasets from elsewhere in Newfoundland, to develop and then test hypotheses regarding the major environmental, preservational or evolutionary controls on observed fossil occurrence. Opportunities are available for interested applicants to expand their research to consider nearby sections on adjacent peninsulas, conduct taxonomic work to describe new taxa, or to consider broader basin evolution. There may also be opportunities for successful students to spend an extended period of time at Memorial
University to work closely with the co-supervisor on aspects of process sedimentology and
paleoenvironmental analysis.

Requirements as to the educational background of candidates that would be suitable for the project
Earth Sciences undergraduate or Masters backgrounds preferred.

References

Matthews, J. J., Liu, A. G., Yang, C., McIlroy, D., Levell, B., & Condon, D. J. (2021). A
chronostratigraphic framework for the rise of the Ediacaran macrobiota: new constraints
from Mistaken Point Ecological Reserve, Newfoundland. GSA Bulletin, 133(3-4), 612-624.

This paper presents a time-calibrated fossil occurrence dataset for the Mistaken Point
Ecological Reserve (Avalon Peninsula), which will form the main comparative dataset for
the new data collected in this project.
Hofmann, H. J., O'Brien, S. J., & King, A. F. (2008). Ediacaran biota on Bonavista Peninsula,
Newfoundland, Canada. Journal of Paleontology, 82(1), 1-36.

The original paper documenting Ediacaran fossils on the Bonavista Peninsula, which
includes a preliminary range chart for individual taxa. Multiple discoveries of new surfaces
and taxa by our research group since 2008 have doubled the number of known fossil bearing surfaces.
Mason, S. J., Narbonne, G. M., Dalrymple, R. W., & O’Brien, S. J. (2013).
Paleoenvironmental analysis of Ediacaran strata in the Catalina Dome, Bonavista
Peninsula, Newfoundland. Canadian Journal of Earth Sciences, 50(2), 197-212.

The most recent description of the palaeoenvironments documented within the Catalina
Dome stratigraphic succession. Recent work conducted by Co-S Lowe’s research group
elsewhere on the Bonavista and Avalon peninsulas is refining our understanding of basin
evolution in this region.

PI: Emily Mitchell, Department of Zoology

Project summary
This project will transform our understanding of Ediacaran carbon cycling by quantifying the influence of early animals on carbon flow, particularly the neglected ivesheadiomorphs of the Avalon assemblage. While understanding early animals is hampered by the paucity of analogues with modern animals, the exceptional, in-situ, census preservation of thousands of specimens enables robust quantitative community analyses, rarely applicable in the fossil record, to be used to test hypotheses about early animal life. Drawing on exceptional Newfoundland and southern England fossil localities, the student will focus on quantify the different ways that Avalonian animals could have changed carbon cycling, both when alive and when dead.

Importance of the area of research concerned
The Ediacaran Period (~635–539 Ma) represents one of Earth's most crucial biosphere transitions, culminating in the emergence of complex animal life. Carbon cycling during this interval was markedly unstable, characterised by extreme isotopic excursions whose drivers remain poorly constrained. The emergence of widespread animal life, found in the fossil record as the Avalon assemblage would almost certainly influence organic carbon burial and carbon cycling. However, little is known about the extent and strength of the mechanistic biological processes that contributed to carbon cycling on a community level, and its this community level that biological and ecological processes act on, then scale up to macroecological levels. Understanding how these animals processed, exported, and/or changed organic matter type, distribution and cycling has direct bearing on our interpretation of the early animal biosphere, and on the interpretation of the atmospheric spectra of exoplanets.

What the student will actually do?
The student will conduct systematic fieldwork at key Avalon assemblage localities in Newfoundland (Mistaken Point, Ferryland) and Charnwood Forest, UK, to document ivesheadiomorph occurrences within their palaeocommunity context. Using high-resolution laser-scanning, photogrammetry and image analysis, they will produce quantitative census data on ivesheadiomorph morphology, size-frequency distributions, and spatial relationships with co-occurring Ediacaran taxa. These empirical data will then be used to build carbon flow models of the ecosystems, using agent based models to reconstruct how ivesheadiomorphs decomposed and what proportion of their biomass would have entered the sedimentary organic carbon pool. Together, this palaeobiological framework will allow robust estimates of standing biomass and carbon flux attributable to ivesheadiomorphs, forming the biological foundation from which their broader impact on Ediacaran carbon cycling can be evaluated.

Requirements as to the educational background of candidates that would be suitable for the project
Either an earth sciences or biological background. A keen interest in palaeontology is needed, but formal courses/training are not.

References

Mitchell, E.G. and Pates, S., 2025. From organisms to biodiversity: the ecology of the Ediacaran/Cambrian transition. Paleobiology, 51(1), pp.150-173.
Furness, E.N. and Mitchell, E.G., 2025. Photosynthetic fractionation of carbon: A biological driver for the Neoproterozoic Shuram carbon isotope excursion. Precambrian Research, 419, p.107702.
Mitchell, E.G. and Manica, A., 2026. The influence of reproductive mode on resource competition and diversity patterns in Ediacaran early animal communities. Nature Ecology & Evolution, 10(7), pp.1234-1244

PI: Oliver Shorttle, Department of Earth Sciences and Institute of Astronomy
Co-I: Alex Archibald, Yusuf Hamied Department of Chemistry, Mark Wyatt, Institute of Astronomy

Project summary
This project will investigate how cosmic dust can affect the climate and atmospheric chemistry of young planets. Planets are initially bathed in vast quantities of debris left over from their formation. As well as the largest debris causing giant impacts, this debris produces a constant rain of dust into planetary atmospheres, affecting chemistry and climate in ways unique to small chemically reactive particles. As a process occurring when planets are still cooling from their accretion and evolving towards their eventual climate state, cosmic dust fluxes have the potential to have lasting effects on the habitability of young planets. This project will conduct simulations to investigate dust production, delivery and climate impacts on young planets.

Importance of the area of research concerned
The evolution of life on Earth has been strongly influenced by interaction with material delivered from elsewhere in the Solar system – that is, asteroids, comets and dust in the zodiacal cloud. Delivery of such material to Earth has been linked to ice ages and mass extinctions. Whilst the impacts of large bodies has received the most attention, there is increasingly awareness that the vast amounts of dust produced by asteroids and comets can itself have a significant climate impact. The bright exozodiacal dust disks found around nearby young stars show that the same processes shaping Earth’s history must also be occurring on exoplanets, often on a much larger scale. It is thus important to determine the effect that this delivery of exogenous material may have had on the conditions on potentially habitable planets, and so its effect on the development and evolution of life.

What the student will actually do?
This project has three main objectives the student will work through, each focussed on modelling, with potential application to the solar system and exoplanetary systems:

Model the flux of dust arriving into the atmospheres of young (exo)planets according to remnant debris properties, planetary system architecture and planetary properties
Model the effect this cosmic dust can have on radiative balance of (exo)planets, including
cloud/hazes formation and how this depends on the background (exo)planet atmosphere.
Model the effect this cosmic dust can have on a (exo)planet’s atmospheric and surface
chemistry.

Requirements as to the educational background of candidates that would be suitable for the project
Students with quantitative backgrounds in Physics, Astrophysics, Chemistry or Earth Sciences would be suitable applicants for this project.

References

Archibald et al., 2020, GMD, 13, 1223
Schmitz et al. 2019, Sci. Adv., 5, 9, eaax4184
Rigley & Wyatt 2020, MNRAS, 497, 1143
Walton et al. 2024, Nature Astronomy, 8, 556

PI: Paul B. Rimmer, Cavendish Laboratory, Department of Physics, University of Cambridge

Project summary
How did life's molecular building blocks join without enzymes, despite water's tendency to hydrolyse their bonds? This project will experimentally test three possible solutions: formamide as an alternative solvent, geochemically accessible ionic liquids, and activation and ligation chemistry in water based on thiocyanogen. Work will begin by testing formamide stability, informed by preliminary results that challenge a published UV-photolysis estimate. Later experiments will be chosen in light of those results. The project aims to define environmental constraints linking particular chemical ingredients and pathways to the planetary settings that can sustain them.

Importance of the area of research concerned
Life depends on water, yet water also hydrolyses the bonds of many biomolecular polymers. Modern organisms solve this problem, mostly by using enzymes, but enzymes are built out of those same polymers. This leads to the question: how did life’s first polymers form? This project will explore three candidate answers: formamide as an alternative or mixed solvent; ionic liquids, such as glycinium hydrogen sulfate; and activation chemistry enabling condensation or ligation in water. The project will test the environmental stability and chemical accessibility of representative systems for each of these three cases. The resulting constraints will show which of these three can be ruled out under plausible planetary conditions.

What the student will actually do?
The student will begin by measuring the hydrolytic and UV stability of liquid formamide over prebiotically relevant ranges of pH, temperature and UV intensity, using spectroscopy and kinetic analysis to reassess the estimate of Boden and Back (1970). Depending on the results, the student will pursue one or both of two further directions. They may investigate the UV stability and chemical behaviour of a plausible planetary ionic liquid, such as glycinium hydrogen sulfate, under relevant conditions. Alternatively, they may investigate prebiotic production of thiocyanogen by photochemical oxidation of thiocyanate, focusing on nitrite, nitrate and other plausible oxidants, and test its use in activation and ligation chemistry. Across the project, experiments will be quantitatively modelled to identify conditions compatible with each pathway and distinguish genuine environmental plausibility from merely successful laboratory chemistry.

Requirements as to the educational background of candidates that would be suitable for the project
Chemistry is preferred. Applicants with backgrounds in chemical physics, physics, planetary science or closely related subjects will also be suitable, especially where they can demonstrate aptitude for experimental chemistry and quantitative analysis.

References

Boden, J. C. & Back, R. A. (1970). Photochemistry and free-radical reactions in formamide vapour. Transactions of the Faraday Society, 66, 175-182. https://doi.org/10.1039/TF9706600175
Lakubivskyi, I., Seager, S., Morrissey, L. S., Georgiou, A. P., Seager, M. D., Agrawal, R. & Petkowski, J. J. (2025). Miscibility of Hydrogen Sulfate Planetary Ionic Liquids with Water. The Planetary Science Journal, 6(12), 304. https://doi.org/10.3847/PSJ/ae260d
Marinic, B., Ritson, D. J., Wordsworth, R. & Sutherland, J. D. (2026). Prebiotically Plausible Synthesis of N-Cyanoimidazole for Phosphate Activation and Templated RNA Ligation. Journal of the American Chemical Society. https://doi.org/10.1021/jacs.6c16138

Testing stellar forcing of heredity: replication and mechanism for a solar-cycle-associated shift in the human de novo mutation spectrum

PI: Tim Hearn, Chronomic Medicine Group, Department of Genomic Medicine, University of Cambridge

Project summary
The ultraviolet-context fraction of new germline mutations tracks the solar cycle, a signal that survived every confounder our pilot tested yet lacks the mechanistic signature of ultraviolet damage — so it can be neither dismissed nor believed. This PhD will resolve it. The student will seek replication in an independent trio cohort, replace birth-year exposure with conception-window modelling against surface UV-B, photoperiod and complementary solar indices, and test candidate mechanisms directly. They will also extend the parent-of-origin resource built in the pilot: 299,814 phased mutations across 11,539 families, the first at this scale for the cohort.

Importance of the area of research concerned
De novo mutations — present in a child but in neither parent — are the ultimate source of heritable variation and a leading cause of severe rare disease. Their rate is known to depend on parental age. Whether the predictable environmental cycles a planet experiences also shape them is untested. The sharpest version of that question runs through ultraviolet light: solar activity varies over an ~11-year cycle, modestly altering the biologically relevant UV reaching the surface, and UV leaves a distinctive mutational fingerprint. Because germ cells are shielded, the prior against such an effect is strong — which is why a well-powered test is informative whichever way it falls. Our just-completed pilot in the 100,000 Genomes Project found a robust, confounder-resistant association between the UV-context fraction of germline C→T mutations and the sunspot number, but without the mechanistic hallmarks of UV mutagenesis. Resolving it is a well-defined, data-rich doctoral project.

What the student will actually do?
Working in the Genomics England Research Environment (approved project 1306) and comparable secure environments, the student will pursue four strands.

Replication: apply the pilot's pre-specified UV-context-versus-CpG contrast to an independent trio cohort with birth-year information — the decisive test of whether the association generalises or is peculiar to these data.
Exposure: move from birth year to conception and gestation windows, and from sunspot number alone to surface UV-B, photoperiod, F10.7 cm flux and Mg II index, asking whether a real signal strengthens under a better-specified physical exposure.
Mechanism: interrogate tandem CC→TT and doublet substitutions, signature-level decomposition, parent-of-origin asymmetry and lag structure, to separate a non-canonical UV process from an unidentified feature of the cohort.
Resource: extend the phased catalogue to new data releases and apply it to germline questions beyond the solar hypothesis. Throughout, the student will use overdispersion-aware models, permutation and scan-aware nulls, and fully reproducible notebooks.

Requirements as to the educational background of candidates that would be suitable for the project
We welcome applicants from genetics, genomics, biological or biomedical sciences, statistics, mathematics, physics, astrophysics, computer science, epidemiology, or a related quantitative discipline. No prior genomics is required. The essential qualities are quantitative aptitude, comfort with (or clear willingness to learn) programming in R or Python, and genuine interest in working across the biological and physical sciences. Applicants from a life-science background should be comfortable with quantitative work; those from a physical-science or computational background will be supported in acquiring the genomics.

References

Hearn T. Parent-of-origin resolution of de novo mutation across the 100,000 Genomes
Project, and a solar-cycle-associated shift in the ultraviolet-context mutation spectrum. Manuscript in preparation, 2026. — the pilot study on which this project builds.
Kong A, Frigge ML, Masson G, et al. Rate of de novo mutations and the importance of father's age to disease risk. Nature. 2012;488:471–475.
Houghton A, Munster EW, Viola MV. Increased incidence of malignant melanoma after peaks of sunspot activity. Lancet. 1978;1:759–760.

PI: Alex J. W. Thom, Yusuf Hamied Department of Chemistry, University of Cambridge

Project summary
This project will develop and apply computational methods to predict which prebiotic molecules survive ultraviolet excitation and why, addressing a possible physical origin of life’s molecular alphabet. Combining electronic-structure theory with nonadiabatic photochemistry, we will investigate how nucleobases and related heterocycles degrade or re-form after irradiation. We will develop quantitative measures of molecular persistence and photochemical escape, examining their dependence on molecular structure, excitation wavelength and solvent environment, and assess whether the resulting comparative measure can be extended to more complex prebiotic molecules.

Importance of the area of research concerned
Why did life adopt its particular molecular building blocks from the wider range potentially available on the early Earth? Ultraviolet radiation may have contributed to this selection through differences in molecular photochemical stability. Studies of nucleobases and their alternatives show that small structural changes can strongly alter the pathways by which electronic excitation is dissipated [1]. However, explaining rapid relaxation alone does not establish the probability of lasting chemical change. This project will develop computational approaches to distinguish recovery of the original molecule, reversible transformation and photochemical escape into other products. Comparing nucleobases with plausible prebiotic alternatives will test whether biological building blocks possess distinctive mechanisms that suppress escape. The resulting molecular understanding will underpin tests of the photochemical-sink hypothesis: that some molecules persist unusually effectively under irradiation, potentially contributing to chemical selection before biological evolution.

What the student will actually do?
The student will begin with adenine and related prebiotic heterocycles, calculating absorption spectra and competing photochemical pathways [1]. Established multireference methods, including state-averaged CASSCF and XMS-CASPT2, will provide benchmarks for reaction energetics and help characterise excited-state minima and conical intersections [2]. Alongside these, the student will explore alternative electronic-structure approaches, building on the group’s nonorthogonal configuration interaction (NOCI) methods [3], to describe the states and couplings governing photochemical persistence. Nonadiabatic dynamics will investigate branching between parent-molecule recovery and photoproduct formation. Selected pathways will be followed beyond electronic relaxation to distinguish transient transformation from persistent chemical escape. The student will assess methodological accuracy and computational cost, and estimate photochemical yields or bounds where rare events limit sampling. Selected solvent effects and representative UV spectra will then be explored, supporting the development of a comparative persistence measure with potential application to more complex prebiotic molecules.

Requirements as to the educational background of candidates that would be suitable for the project
Applicants with backgrounds in chemistry, physics or closely related subjects would be suitable. A strong foundation in quantum mechanics and mathematics is needed and some programming experience would be useful, but training will be provided. Previous experience in photochemistry or origins-of-life research is not required.

References

Serrano-Andrés, L., Merchán, M. and Borin, A. C. (2006). Adenine and 2-aminopurine: paradigms of modern theoretical photochemistry. Proceedings of the National Academy of Sciences, 103, 8691–8696. doi:10.1073/pnas.0602991103
Sicilia, F., Blancafort, L., Bearpark, M. J. and Robb, M. A. (2008). New Algorithms for Optimizing and Linking Conical Intersection Points. Journal of Chemical Theory and Computation, 4, 257–266. doi:10.1021/ct7002435
Burton, H. G. A. and Thom, A. J. W. (2019). General Approach for Multireference Ground and Excited States Using Nonorthogonal Configuration Interaction. Journal of Chemical Theory and Computation, 15, 4851–4861. doi:10.1021/acs.jctc.9b00441

PI: Helen Williams, Department of Earth Sciences, University of Cambridge
Co-I: Rayssa Martins, Department of Earth Sciences, University of Cambridge & Ross Findlay, Department of Earth Sciences, University of Cambridge

Project summary
The asteroids that supplied volatile-rich material to the early Earth no longer survive in their original form, but their meteoritic remnants preserve lithologically diverse and pervasively water-altered fragments. This project will combine high-resolution imaging with water and stable Fe–Zn isotope analyses to constrain the extent, pathways and chemical consequences of fluid transport within primitive asteroids. By resolving aqueous alteration and element redistribution at the scale of individual lithologies, the project will reconstruct how parent-body processing modified the chemical inventories preserved in these planetary building blocks.

Importance of the area of research concerned
Understanding how life-essential volatiles were processed in the early Solar System is central to the question of how life arose in the first place. Carbonaceous chondrites, remnants of some of the earliest and most water- and organic-rich asteroids in the Solar System, are widely used as proxies for the volatile-rich material available during planetary accretion. However, the extent and pathways of aqueous alteration, fluid transport and associated chemical redistribution within their parent bodies remain poorly constrained, which is problematic when considering these meteorites as proxies for planetary building blocks. This issue is further complicated by the innate heterogeneity of these meteorites, as bulk chemical analyses seldom aid in elucidating their complex histories. Addressing this problem requires a holistic, lithology-scale approach that integrates mineralogical and isotopic tracers of mineral-fluid reaction pathways. Resolving these effects is essential before carbonaceous chondrites can be confidently used as tracers of prebiotic chemistry's raw materials.

What the student will actually do?
The successful PhD student will characterise a broad range of phyllosilicate-rich chondritic materials, including CM, CR and C2-ungrouped carbonaceous chondrites, by mounting, polishing and using scanning electron microscopy to identify distinct lithologies, alteration textures and secondary mineral assemblages [1]. Water isotopes will then be measured using a thermogravimetric analysis–cavity ring-down spectrometer system as water is released from extraterrestrial hydrated minerals at different temperatures, allowing isotopic differences between water-bearing components to be resolved [2]. Bulk and targeted lithologies will also be analysed for mass-dependent Fe and Zn isotope compositions. Fe isotopes will trace redistribution associated with aqueous oxidation, dissolution and secondary mineral formation, while Zn isotopes will provide a more fluid-mobile tracer of solute transport [3]. Together, these datasets will constrain the pathways, scale and chemical consequences of aqueous fluid transport within primitive asteroid parent bodies.

Requirements as to the educational background of candidates that would be suitable for the project
This project will suit an enthusiastic and highly motivated individual, preferably with a degree in geoscience, cosmochemistry of planetary science, or someone with a chemistry background and relevant laboratory experience.

References

[1] Suttle et al., (2022) Meteoritics and Planetary Science, 59: 1043-1067
[2] Oerter et al., (2026) Geochemica et Cosmichimica Acta, 418: 79-96
[3] Pringle et al., (2017) Earth and Planetary Science Letters, 468, 62-71

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Research proposals 2026-2027