Evolution under extraterrestrial conditions

Microbes in Pyroclastic Rocks on Earth and the Search for Life on Mars

PI: Bastiaan Ibelings

Collaborators: Mridul Thomas, Dan McGinnis, and Luca Caricchi

Funding: DIP

Dates: 01.11.2022 – 31.10.2026

Description : 

The study of the geomicrobiology of volcanic rocks on Earth offers a unique opportunity to get answers about the origin of life on Earth and the search for life on other planets like Mars. Interestingly, deposits that are the consequence of explosive eruptions (ignimbrites, pumice, tuff, see image) have remained vastly understudied compared to the larger attention given to effusive eruptions (lave flows). A PhD's work  starts from the point of view that the ability of porous volcanic rocks to host life, or well-preserved signs of life, under highly stressful conditions such as high UV, CO2 or extreme temperature fluctuations, seems to be exceptional and warrants further study. To this end, a PhD student is undertaking controlled experiments using rocks of varying porosity under conditions that mimic – aspects of - the Martian environment, testing for survival and growth of  2 selected microorganisms, a Cyanobacterium (Chroococcidiopsis cubana) and an Actinobacterium (Geodermatophilus africanus). The rocks before and after exposure and microbial development will be analyzed with inter alia SEM images and Raman spectroscopy to understand the biosignatures left by the microbes on these rocks after exposure to Martian conditions 

Job opportunities:

  • One PhD (Francesca Bertolino): Survival and growth of bacteria in the Martian environement.


Experimenting with early life on Mars

PI: Emeline Bolmont, Bastiaan Ibelings, Dan McGinnis

Collaborators: Mridul Thomas, Luca Caricchi, Sébastien Castelltort, Nina Zeyen (UniGE), Brice-Olivier Demory (University of Bern), Mathilda Fatton (University of Bern and Neuchâtel), Lucas Patty (University of Bern), Antoine Pommerol (University of Bern), Maria Schönbächler (ETH Zurich)

Funding: PlanetS

Dates: 01.01.2024 – 31.12.2026


Life must have emerged very early on primitive Earth. Indeed, the first signs of biogenic microfossils date as far back as 3.4 Gyr in the Archean. On primitive Earth, most of the surface was submerged but it is possible that subaerial regions, most likely felsic, were present already early in the Earth's history when life was not yet present or extremely scarce. Consequently, chemoautotrophs (bacteria that derive energy from the oxidation of inorganic compounds) could have been one of the earliest possible types of bacteria on Earth. Around the same time on Mars, liquid water was flowing on the surface creating networks of rivers, lakes and seas. Some studies show that mixtures of gasses such as CO2+H2 could lead to surface conditions allowing for liquid water during that period despite the faint young Sun. At that time on Mars, there was already a diversity of rocks and minerals, including extensive outcrops of volcanic basalts in aqueous and subaerial conditions. Additionally, there were also fluvio-lacustrine sedimentary rocks associated with river systems and containing for instance plagioclases, pyroxenes, quartz and significant amounts of clay minerals (phyllosilicates). In that context, we ask the question: what could life on Early Mars have been like, and if life survived until now on Mars where would it be and how would it appear using current Martian rover technologies? This proposal will investigate the survivability, growth and evolution of Methanococcus maripaludis in different environments, which could be representative of early Mars.

This project builds on a previous project led by Dr. Asena Kuzucan who looked at the survivability of E. coli in different atmospheres, which could be representatives of exoplanets atmospheres (Kuzucan et al. in prep).

Job opportunities:

  • One Postdoctoral researcher (Dr. Asena Kuzucan): Experiments on survival and evolution of bacteria under early Mars environment.