Spectroscopic investigation of a potential Mars analog site: Lake Bagno dell’acqua, Pantelleria, Italy

Analog sites on Earth are places characterized by one or more features similar to those observed or inferred on planetary surfaces (e.g. [1]). So far, many sites have been identified and studied, but many other potential analog sites still need to be characterized. Concerning Martian analog sites, one interesting area is Lake Bagno dell’Acqua, which is an endorheic (closed) alkaline (pH ≥ 9) lake located in the island of Pantelleria in Sicily, Italy. The lake was proposed to be a Martian analog site [2] but while there are a few mineralogical investigations of the lake sediments [3-4], so far, a comprehensive characterization of the lake is lacking. We report here the combined Visible to Near Infra–Red (VNIR) reflectance and Raman Spectroscopy investigation of a suite of nineteen samples from the studied area. The organic fraction of the samples was also investigated (DNA sequencing and fluorescent microscopy) to describe its composition and the spatial distribution of microbial communities. Our investigation will improve the comprehension of sediments derived by alkaline aqueous alteration and highlights the complex interplay between organic matter and inorganic matrix.