I'm a third year PhD student at the University of St Andrews in the Schools of Physics and Astronomy
and Earth and Environmental Sciences and visiting researcher at the Space Research Institute at the Austrian Academy of Sciences in Graz.
My research is focusing on the effect of lighting on the atmospheric chemistry of Earth and other planets and
investigating its impact on the origin of life.
This includes Miller-Urey like sparking experiments and simulations of chemical processes in planetary atmospheres.
The role of lightning for life on the early Earth
Lightning might have played an important role in the origin of life, and we know that it can produce nutrients for life in the atmosphere of the early Earth.
But so far it was not possible to say if lightning was an important source of nutrients for the earliest life on Earth.
We conducted spark experiments in our lab with different gas mixtures: N2 and O2 for the modern Earth and N2 and CO2 for early Earth. We then measured the concentration of the nitrogen products such as nitrite and nitrate and their isotopic composition.
We found lightning can efficiently produce nitrogen oxides in both O2- and CO2-rich atmospheres, which beyond Earth, provides a potential source of nutrients for life on exoplanets.
Our nitrogen signature for lightning cannot explain nitrogen samples in the Archean sedimentary rock record, suggesting that lightning was not a major source of nutrients for life on early Earth and that biological nitrogen fixation developed very early.
However, there is one set of samples from the Isua Greenstone Belt in Greenland from nearly 3.8 billion years ago, that shows an isotope signature that can be explained by a lightning contribution.
And our isotopic signature can help to investigate the source of nitrate samples on Mars and potentially other bodies in the Solar System.
For more information please check out our paper (DOI, Full text, Arxiv) and for a more detailed summary our Research Briefing (Full text).
High-energy radiation in planetary atmospheres
We investigate the effect of stellar X-ray and UV (XUV) radiation, cosmic rays (CR), and stellar energetic particles
(SEP, mainly protons) on the atmospheric chemistry of the hot Jupiter HD 189733b and identify key signatures of these interactions.
We choose this planet because it is one of the best studied and observed exoplanets today, allowing us to optimize the model before
later applications to habitable worlds. We use 3D simulations of HD 189733b’s atmosphere for the pressure-temperature profiles and
XUV spectra of the host star from the MOVES collaboration. To model the chemical reactions, we use the STAND2019 network, which
includes ion-neutral C/H/N/O chemistry. We study in detail the formation of the amino acid glycine and its precursors. Our results
suggest that the CR and SEP influx enhances the formation of glycine, while XUV radiation leads to a depletion of glycine in the
upper atmosphere. We identify ammonium (NH4+) as an important signature of CR and SEP influx, even though the degree of ionization
of the atmosphere remains low. XUV radiation strongly ionizes the upper atmosphere, mainly producing H+ and He+. Ultimately, we show
that high energy processes increase glycine and precursor production and thus may potentially play an important role in prebiotic chemistry.
For more information please check out our paper (DOI, Arxiv).
Magma ocean evolution of the TRAPPIST-1 planets
Recent observations of the potentially habitable planets TRAPPIST-1 e, f, and g suggest that they possess large water mass fractions
of possibly several tens of weight percent of water, even though the host star's activity should drive rapid atmospheric escape.
These processes can photolyze water, generating free oxygen and possibly desiccating the planet.
After the planets formed, their mantles were likely completely molten with volatiles dissolving and exsolving from the melt.
To understand these planets and prepare for future observations, the magma ocean phase of these worlds must be understood.
To simulate these planets, we have combined existing models of stellar evolution, atmospheric escape, tidal heating, radiogenic heating,
magma-ocean cooling, planetary radiation, and water-oxygen-iron geochemistry. We present MagmOc, a versatile magma-ocean evolution model,
validated against the rocky super-Earth GJ 1132b and early Earth.
This model is part of the VPLanet code.
We simulate the coupled magma-ocean atmospheric evolution of TRAPPIST-1 e, f, and g for a range of tidal and radiogenic heating rates,
as well as initial water contents between 1 and 100 Earth oceans.
We also reanalyze the structures of these planets and find they have water mass fractions of 0–0.23, 0.01–0.21, and 0.11–0.24 for
planets e, f, and g, respectively.
Our model does not make a strong prediction about the water and oxygen content of the atmosphere of TRAPPIST-1 e at the time of mantle solidification.
In contrast, the model predicts that TRAPPIST-1 f and g would have a thick steam atmosphere with a small amount of oxygen at that stage.
For all planets that we investigated, we find that only 3–5% of the initial water will be locked in the mantle after the magma ocean solidified.
For more information please check out our paper (DOI,
Arxiv) and our GitHub repository.
- Barth, P., et al. 2023, Isotopic constraints on lightning as a source of fixed nitrogen in
Earth's early biosphere, Nature Geoscience. DOI (Full text, Arxiv), Research Briefing (Full text)
- Rogers-Lee, D., et al., incl. Barth, P., 2023, The energetic particle environment of a GJ 436 b-like planet, MNRAS 521, 5880. DOI, Arxiv
- Raymond, S. N., et al., incl. Barth, P., 2022, An upper limit on late accretion and water delivery in the TRAPPIST-1 exoplanet system, Nature Astronomy 6, 80–8. DOI, Arxiv
- Barth, P., et al. 2021, Magma Ocean Evolution of the TRAPPIST-1 planets, Astrobiology 21, 11. DOI, Arxiv
- Barth, P., et al. 2021, MOVES IV. Modelling the influence of stellar XUV-flux, cosmic rays, and stellar energetic particles on the atmospheric composition of the hot Jupiter HD 189733b, MNRAS, 502, 6201. DOI, Arxiv.
- Woitke, P., et al., incl. Barth, P., 2021, Coexistence of CH4, CO2 and H2O in exoplanet atmospheres, A&A 646, A43. DOI, Arxiv.
- Barnes, R., et al., incl. Barth, P., 2020, VPLanet: The Virtual Planet Simulator, PASP 132 024502. DOI, Arxiv.
- Carone, L., Baeyens, R., Mollière, P., Barth, P., et al. 2020, Equatorial retrograde flow in WASP-43b elicited by deep wind jets?, MNRAS, 496, 3582. DOI, Arxiv.
You can find a full list of my publications here.
- October 2022: Graz-Viena Exoplanet Scientists Meeting, Vienna, Austria
- August 2022: NoR-CEL meeting, St Andrews, UK
- July 2022: Leverhulme Centre for Life in the Universe, Cambridge, UK
- May 2022: EGU General Assembly 2022, Vienna, Austria
- March 2022: Hypatia Colloquium Series, ESO (online)
- February 2022: St Andrews Interdisciplinary Science Conference, UK
- September 2021: AbGradCon 2021, Tokyo, Japan (online)
- July 2021: Goldschmidt 2021, Lyon, France (online)
- May 2021: NASA 'Quantifying Habitability' Science Working Group (online)
- April 2021: vEGU21 (online)
- March 2021: NoR-CEL meeting, St Andrews, UK (online)
- November 2020: CHAMELEON Kick-off meeting, St Andrews, UK (online)
- November 2020: Out Thinkers (LGBT+ STEM Week), St Andrews, UK (online)
- October 2020: Scottish Exoplanet and Brown Dwarf Meeting, Edinburgh, UK (online)
- July 2020: NOVO Nordisk Meeting, Niels Bohr Institute, Copenhagen, Denmark (online)
- June 2020: StA-CES Summer Meeting, St Andrews, UK (online)
- December 2019: PSF-Coffee, MPIA, Heidelberg, Germany
- October 2019: VPL Meeting, University of Washington, Seattle, US
- August 2019: StA-CES Summer Meeting, St Andrews, UK
- March 2019: General Meeting SPP 1833 Habitable Earth, DFG, Cologne, Germany
- April 2017: (G)Astro-Seminar, jDPG, Bad Kreuznach, Germany
- January 2017: PSF-Coffee, MPIA, Heidelberg, Germany
- January 2022: LGBTQ+ STEMinar 2022
- September 2020: RAS Early Career Poster Exhibition 2020. Poster
- August 2020: STEM Village Virtual Symposium 2020
- July 2020: Exoplanet 3, Heidelberg, Germany
- April 2020: UKEXOM, Birmingham, Germany (postponed due to COVID-19)
- March 2020: Cloud Academy 2, Les Houches, France (postponed due to COVID-19)
- September 2019: EPSC-DPS Joint Meeting, Geneva, Switzerland (presented by Ludmila Carone)
- June 2019: AbSciCon, Seattle, US (presented by Rory Barnes)
- June 2019: Star-planet interaction workshop, Ringberg, Germany (presented by Ludmila Carone)
During my PhD I had various opportunities to participate in outreach projects.
2019 - 2022, I was a presenter at the Mobile Planetarium, where PhD students in Astronomy at the University of St Andrews visit nearby primary schools and science festivals to give shows in a portable planetarium dome.
2020 - 2022, I was also registered as a STEM ambassador in Scotland, a network of volunteers working in or studying STEM subjects who bring these STEM subjects alive for young people around Scotland.
In March 2022, I created a video for the Global Science Show (STEM Ambassador Edition).
And I was able to talk about exoplanets research to different audiences, such as at Dundee Science Centre and different Astronomical Scoieties throughout the UK.
In April 2023, I was on the Austrian children TV ZIB Zack Mini to talk about the shape of the Universe.
You can find a CV with my detailed outreach experience here.
Steiermark Schau 2023
The Steiermark Schau is an exhibition presenting the diversity of the Austrian state of Styria.
In 2023, the focus of this exhibition is "Diversity of life", and a central element will be an 800 squaremetre mobile pavilion.
In cooperation with the IWF in Graz and following the theme "Atmospheres - Climate, Art, and Cosmos", a combination of art works and scientific reflections will be presented on a large projection space, encouraging the audience to think about the fragility of our own atmosphere in the context of the large diversity of extrasolar planets and their atmospheres.
In preparation of this exhibition, it is my role to coordinate the cooperation between exoplanet scientists at the IWF and the organisers of the project as well as the participating artists.
Around Distant Suns
"Around Distant Suns" is an anthology of nine science fiction stories, edited by Emma Puranen.
Each story is written by a pair of one creative writer and one researcher of the St Andrews Centre for Exoplanet Science.
I worked with Emma Puranen on the short-story "A Spark in a Flask" which follows a roboter who oversees giant spark experiments on a base on the moon, long after the last humans left.
These experiments are designed to find under which conditions life might emerge in the presence of lightning and are similar to the famous Miller-Urey experiment and the experiments that I am conducting in my lab.
"Around Distant Suns" is available at Guardbridge Books.
"A Spark in a Flask" was selected for the Best of British Science Fiction 2021 award anthology.
- 2022 - now: PhD student at the Space Research Institute of the Austrian Academy of Sciences, Graz
- 2019 - now: PhD in Astronomy at the University of St Andrews, UK
- 2017 - 2019: M.Sc. in Physics at the University of Heidelberg, Germany
Thesis: Open Source and Versatile Magma Ocean Evolution Model for Terrestrial Exoplanets and its Application to the TRAPPIST-1 Planets. Max Planck Institute for Astronomy, Heidelberg
- 2017 - 2018: Study abroad at the University of Washington, Seattle, WA, US
- 2013 - 2017: B.Sc. in Physics at the University of Heidelberg, Germany
Thesis: Large-Scale Circulation with Cloud Formation in Planetary Atmospheres. Max Planck Institute for Astronomy, Heidelberg
You can find my full CV here and a CV with my detailed outreach experience here.
Patrick Barth (he/him)
Post graduate researcher
School of Physics and Astronomy
University of St Andrews
KY16 9SS St Andrews, UK