Researchers from Keralam have identified two key minerals in parts of Tamil Nadu and the Atacama Desert in Chile, which reflect geological, chemical and physical similarities with Mars, and have helped establish these areas as Martian analogue sites.

The research team from the Kerala University, led by Sajin Kumar K.S., Associate Professor, Department of Geology, and project coordinator, DST-FIST, identified melanterite in Neyveli, Tamil Nadu, and gypsum in the Atacama Desert and the Tiruchirappalli Badlands, a semi-arid geological and paleoclimatic terrain in Tamil Nadu.

Both minerals are hydrous sulphates that record water–rock interactions. While gypsum preserves evidence of past aqueous environments, melanterite indicates short-lived wet, acidic and oxidising conditions. These processes are relevant to those inferred on Mars. Thus, these terrestrial minerals provide useful analogues for understanding past water activity and potentially habitable environments on Mars, the researchers point out.

They added that identifying terrestrial analogue sites has become a pressing requirement in the era of intense planetary exploration since recent studies demonstrated that orbital data alone cannot fully characterise Martian minerals. High-precision, state-of-the-art analytical tools are essential for such investigations.

Advanced instrumentation, including a laser Raman spectrometer, were used for the identification. The DST-FIST (Fund for Improvement of S&T Infrastructure in Universities and Higher Educational Institutions)-supported spectrometer was used to detect the distinctive spectral fingerprints of the minerals and confirm their identification.

The findings have been published as two research papers in the Journal of Geophysical Research: Planets, a leading journal on planetary science. 

According to the study, such findings are believed to be crucial in advance planetary science by improving human understanding of past habitable environments on Mars and other planetary bodies. Identifying minerals capable of recording water activity and preserving biosignatures can also help guide future planetary missions toward the most promising locations in the search for evidence of life beyond Earth.

The team is now focusing on rare analogue sites in extreme conditions across different parts of the globe to understand primitive life for astrobiological studies, using the same facility.