GAS’ campaign to Río Tinto, a Mars analogue site

Anshuman Bhardwaj and Juan Antonio Ramírez Luque, members of the Group of Atmospheric Science (GAS), in collaboration with David Fernández Remolar, a former member of the Group, are going to carry out a field site campaign in one of the most renowned Mars analogue sites on Earth: Río Tinto, in southwest Spain. The project, which has been partly funded by Europlanet and the Wallenberg Foundation, is meant to study the mineralogy derived from acidic salts and its evolution with regards to the associated biological activity.

Río Tinto, Spain. Credits: Paco Naranjo Jiménez

The formation through evaporation of the discovered acidic minerals (evaporites) in some regions on Mars is not totally understood, and Río Tinto offers the same environmental conditions that are thought to have been present on the remote past of the planet. Provided that life ever emerged and adapted to those conditions, it could be possible that its traces are still there. One of the main goals of the study is to plot the evolution of the salt deposits, from their origin to the formation of minerals (what in Río Tinto can be observed along the course of the water streams on the area), and biosignatures left behind by the native organisms. By going into depth in the knowledge of the involved processes, it will be possible to ascertain what should be sought when investigating signs of life on the planet, whose surface seems to have been dominated by global acidic conditions according to the minerals widely found in different regions (sulphates and oxide minerals).

Therefore, the project will focus on the study of the mineral matrix formed under these conditions along tens of millions of years, tracking back its change while looking for the preserved biosignatures if any. If these latter are demonstrated, the study will mean a new and highly relevant reference for the selection of landing sites in the future exploration of Mars in search for signs of past life, as well as for the selection and manipulation of samples to be returned to Earth by the Mars 2020 cache system.

GAS's drone

Along this same line, another task to be developed during the campaign is the performance of a high-resolution Digital Terrain Model (DTM) of the sampling points by means of an Unmanned Aerial Vehicle (UAV). Apart from providing context and additional information about the topographical distribution of the target minerals for the geochemical study, the use of this technology will permit the identification of similar environments on Mars by applying imagery analysis.