Extreme Iceland: exploring the limits of life

Why are the environments of Northeast Iceland captivating to astrobiologists? Discover the fascinating projects from a recent fieldtrip which shed light on these environments.

The extreme environments of Northeast Iceland emulate those seen on extra-terrestrial moons and planets, and therefore offer a unique look into exoplanet habitability.

A team of nine researchers from the School of Physics and Astronomy and School of Chemistry took part in a recent fieldtrip near Akureyri in North East Iceland. In this article they share details of their projects.

The researchers are part of the UK Centre for Astrobiology (UKCA), which seeks to explore the limits of life, the potential for life elsewhere in the universe, and the ability to detect biosignatures on otherwise barren worlds. This fieldtrip was designed to advance these goals and was generously funded in this endeavor by the David and Claudia Harding Foundation.

Research projects

The colour of exoplanets

The next generation of space telescopes will be designed to measure the “colour” of exoplanets – how much light they reflect at different wavelengths. Much of Iceland is composed of primitive minerals likely to occur on exoplanets, with minimal plant coverage. By exploring these areas, this project aims to marry ground-based sampling in these regions with satellite infrared “colour” measurements of Iceland, and so learn lessons for interpreting future telescope observations of exoplanets.

Clay communities

An investigation is taking place into the microbial communities that inhabit clays in cold Icelandic basalts. Understanding the capabilities of these organisms and their preservation potential in clays has applications to understanding the habitability of newly emerging volcanic environments on Earth and the biogeochemical processes that occur in weathered basaltic materials. This research will have application to volcanic terrains on Mars, including the preservation potential of life in Martian clays which are widely reported across the planet’s surface.

Biomorphs in basaltic terrains

Basaltic rocks are known to weather into products such as palagonite and smectite. Studies of the microbial communities inhabiting such products have showed the presence of non-biological features that were similar to the morphology of microorganisms. A range of life-like forms are also known to develop in mineral deposits formed around hot spring pools. Studies into the biological-like structures in basaltic and hydrothermal environments might offer insight into how life might arise elsewhere.

Plastics in Extreme Environments

Approximately 15% of marine litter ends up at coastlines, with plastics accounting for 60–95% of this debris. With nearly 5,000 km of coastline and a significant coastal population, Iceland is particularly susceptible to this coastal plastic pollution. Interestingly, the materials which make up much of this plastic debris, nylon and polyethylene (used in gillnets and buoys for example), are used in space exploration – nylon is used in space suits, and polyethylene for food packaging and radiation shielding for spacecraft.

Cryo-environments – Permafrost

Permafrost and cryosphere environments are at particular risk from climate change, warming at up to four times the global average. Current models assume that permafrost must first thaw before microbes can resume their metabolisms. However, it has been shown that some microbes can maintain an active liquid cytoplasm far below the freezing point of the external environment. Psychrophilic microorganisms from collected samples will be analysed to understand the biophysics that enable life in sub-zero environments.