Indian Scientists Identify Martian Analogue Sites in Tamil Nadu

Two minerals found in Tamil Nadu and in Chile's Atacama Desert have been used to establish those places as Martian analogue sites, in work announced by the Ministry of Science and Technology on 16 October 2026. An analogue site is a place on Earth whose geology, chemistry and physical conditions resemble those on Mars closely enough to be used as a stand-in for studying the planet.

The two minerals

The study identified melanterite at Neyveli in Tamil Nadu, and gypsum in the Atacama Desert of Chile and in the Tiruchirappalli Badlands, a semi-arid geological and palaeoclimatic terrain in Tamil Nadu. Both are hydrous sulphates, which means they hold water in their crystal structure and therefore record how water and rock once interacted.

Melanterite at Neyveli forms from marcasite in the lignite substratum through sulphide oxidation, a process similar to the one thought to create sulphates on Mars. Gypsum, on the other hand, preserves evidence of older water-rich environments and can trap biosignatures inside its mineral matrix, which makes it valuable in the search for traces of life.

Who did the work and how

The research team came from the University of Kerala and was led by Dr. Sajin Kumar K. S., Project Coordinator of DST-FIST. The key instrument was a laser Raman spectrometer supported under DST-FIST at the university's Department of Geology, which picks up the distinctive spectral fingerprint of each mineral and so confirms its identity. The findings were published as two research papers in the Journal of Geophysical Research: Planets.

Why analogue sites matter

Planetary scientists increasingly argue that data from orbit alone cannot fully describe Martian minerals, so high-precision laboratory study of look-alike terrain on Earth has become a pressing need. Minerals that record water activity and can preserve biosignatures help scientists judge which parts of Mars were once habitable, and can guide future missions towards the most promising landing sites. The Kerala team is now looking at rare analogue sites in extreme environments elsewhere in the world to study primitive life for astrobiology.