Minerals are key indicators for habitable environments on rocky planets and they can be detected at multiple scales, from detailed lab measurements, to rocks at outcrops and by remote detection by satellites. But how are the signatures related across these contrasting measurement scales? During Summer 2025 a field team from the University Twente and TU Delft mapped five different geothermal areas in Iceland to find out.
The alteration of basaltic volcanic landforms by water and volcanic heat offers a unique glimpse into the early-Earth and early-life environments. And by extension there terrestrial locations helps us understand what mineral signatures we should look for on other planets such as Mars. The best place to go is Iceland, home to several unique field locations where these geothermal alteration processes can be studied in detail.
Multispectral instrumentation
The field team used a unique hyperspectral camera to detect the minerals at various types of geothermal areas. As the HySpex instrument on top of its tripod pans across the area of interest, the VNIR and SWIR detectors build up a comprehensive image to map the composition of the outcrop. Post-processing after the campaign will bring out the telltale signatures of e.g. clays, sulphates and zeolites; minerals that can allow remote detection of such habitable areas on other planets. Scanning outcrops with this type of camera is not commonplace and it offers a unique and innovative measurement approach. Using a drone to take RGB-images from above, Sebastiaan de Vet from TU Delft surveyed the outcrops and generated 3D terrain models that will help place the detected minerals in context.