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Two PhD positions in exoplanetary physics

Updated: Oct 28, 2022

The newly established Forming Worlds research group at the Kapteyn Astronomical Institute invites applications for two PhD positions focussed on the interior- and atmospheric evolution of young rocky planets for a start in 2023. The prospective students will model the transition from hot magma ocean epochs to cooler climatic and geodynamic regimes of rocky exoplanets. The goal is to interpret upcoming observations of lava exoplanets to gain insights into the formation of the prebiotic atmosphere of Earth.

PhD projects in the Forming Worlds research group

The two projects will focus on a better understanding of the build-up of rocky planetary atmospheres during high-temperature magma ocean epochs. Current and near-future exoplanet surveys such as JWST, TESS, CHEOPS, PLATO, and the ELTs deliver ever-more accurate insights into the atmospheric and surface conditions of rocky planets that are potentially similar to Earth in a number of features. At present, the most favourable targets within the accessible rocky planetary census are high-temperature super-Earths that are either vaporised or molten from intense stellar irradiation. These worlds share characteristics with the magma ocean epoch during the accretion of our own planet, which formed the prebiotic atmosphere of the Hadean Earth.

As a successful applicant, you will develop numerical and theoretical simulation tools to model the interaction of atmospheric volatiles with the planetary interior, applicable to transient (like the Earth's) and long-lived magma ocean epochs, such as those of short-period exoplanets. The goal will be to create blueprints of planetary evolution pathways that enable advanced interpretation of data from exoplanet surveys. Ultimately, this will enable us to constrain the composition and thermodynamics of post-magma ocean atmospheric regimes that are potentially amenable to surficial origin of life scenarios. You will become part of the expanding Forming Worlds research group and will have the opportunity to collaborate with internationally leading scientists from the Alien Earths, AEThER, LIFE, PLATO, and Ariel initiatives, and the Dutch Origins Center.

Informal inquiries about the thematic direction of the positions are welcome and should be sent to

PhD topic 1: Evolution and observability of magma ocean atmospheres

The first project will be dedicated toward a better understanding of the chemical evolution of magma ocean atmospheres. How does the balance between atmospheric loss and sequestration into the planetary mantle shift the composition of the post-magma ocean climate? How do rocky planets with different masses, different metal cores sizes, around different types of stars, or with different initial compositions evolve on geologic timescales? What are the best observational markers for astronomical instruments to test the physics of planetary evolution? What makes the difference between a desiccated world and a potentially habitable one?

PhD topic 2: Geophysics and -chemistry of magma ocean interiors

The second project will focus on the physics and chemistry of planetary interiors during solidification of planetary mantles. How does turbulent convection in the magma ocean affect the redistribution of redox-active elements, such as iron, in the planetary mantle? Do different modes of mantle crystallisation shift the atmospheric balance of major compounds, such as water, to a degree that is observable in exoplanetary systems? How do reduced and oxidised planetary interiors differ in the timescale and dynamics of crystallisation? Which prospects for plate tectonics or different styles of geodynamics and long-lived volcanism have super-Earths?

You should have

Both PhD projects operate within the highly cross-disciplinary spectrum of planetary and exoplanetary sciences. We seek motivated students with a strong background in the physical sciences or geosciences, including, but not limited to, Physics, Astronomy, Geophysics, Geochemistry, Atmospheric Sciences, or Computational Sciences with minors in Physics or Planetary Sciences. Further interdisciplinary training throughout the PhD program will familiarise you with the areas you have not been specialising in during your undergraduate studies.

Successful candidates must hold a Masters degree or equivalent by the starting date of the position. Previous research experience and skills will be important criteria for the selection. Familiarity with Linux/UNIX computer environments, high-performance computing, and Python/C/Julia computer languages is desirable but not required. Applicants may indicate their preference for one of the topics outlined above.

Dutch language skills are welcome but not essential for these posts. English is the common language spoken at the institute, in undergraduate courses, and in research.

Diversity and Inclusion are a part of the mission of the Forming Worlds research group and the Kapteyn Astronomical Institute, as outlined in our group-internal Code of Conduct and the Diversity and Inclusion Policy of the University of Groningen. We embrace diversity and seek candidates who will create a climate that attracts curious students and researchers of all races, nationalities, and genders. We therefore invite applicants from underrepresented groups in particular to apply.

The Kapteyn Astronomical Institute at the University of Groningen

The Kapteyn Astronomical Institute is part of the Netherlands Research School for Astronomy (NOVA) and is recognised worldwide for the quality of its research in multiple areas of astronomy. With 15 faculty and about 50 PhD students, it is the second-largest astronomical institute in the Netherlands. The University of Groningen occupies a strategic place in Dutch astronomy, hosting both the Kapteyn Astronomical Institute, the low-energy astrophysics division of the Netherlands Institute for Space Research (SRON) and the NOVA sub-mm lab. The Kapteyn Institute has a strong connection with the Netherlands Institute for Radio Astronomy (ASTRON) in Dwingeloo, a European centre of radio astronomy research. Staff and PhD students at the Kapteyn Institute frequently collaborate with SRON and ASTRON scientists and engineers. There are also strong interdisciplinary connections with other institutes in the Faculty of Science and Engineering in Groningen, and across the Netherlands, such as with the Dutch Origins Center.


Groningen is a historic university town in the northern Netherlands with a population of approximately 230,000 people, of which almost 25% are students. This makes Groningen the city in the Netherlands with the highest student population density, the youngest city in the country, and one of the youngest in Europe. Groningen offers very high quality of life, surrounded by beautiful nature, and is a lively city with a remarkably diverse cultural scene. You can find more information on GroningenLife!.

Employment Conditions

PhD positions are paid according to the Collective Labour Agreement (CAO) for Dutch Universities. PhD students earn competitive salaries (the current annual gross salary, including allowances, increases from about €35,000 in year 1 to about €44,800 in year 4), and receive internationally outstanding benefits, being eligible for both social security and retirement benefits. All PhD positions are funded for four years.

Informal inquiries about the institute in general, application procedure, and employment conditions are welcome and should be sent to

Application Details

A complete (combined in a single PDF file) application includes the following:

  1. a general cover-letter motivating your application and detailing the motivation to apply for one or more of the proposed PhD projects. Please clearly indicate which projects you apply for, why you apply for them, and rank them in your order of preference. Without motivation and ranking, your application will be harder to assess (1 page max);

  2. a research statement (2 pages max) describing your personal research interests and previous research projects;

  3. your CV/resume;

  4. a certified list of grades from your undergraduate degree(s) up to the moment of application (in case your degree has not yet been awarded).

In addition to the above documents, candidates have to arrange for two reference letters from researchers to be sent by December 1, 2022, to The application deadline is December 1, 2022, at midnight (CET), and the selection of candidates will continue until all positions are filled.

Apply here:

Further information about other topical positions is also given at the website of Kapteyn:

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