A group of scientists managed to identify a previously unknown mineral on the surface of Mars that could change what was known about its past. The discovery was made possible thanks to the use of advanced spectroscopy and revealed a unique signal that had puzzled experts for years.
The study, published by Nature Communications, confirmed that the mysterious spectral signature recorded at 2,236 microns corresponds to ferric hydroxosulfate (Fe³⁺SO₄OH). This mineral only forms under high temperatures and oxidizing conditions. According to the researchers, its presence demonstrates that Mars experienced intense episodes of heat and volcanic activity.
A discovery that rewrites the past of the Red Planet
The signal was detected in two specific areas: Aram Chaos and the Juventae Plateau, within the Valles Marineris system. There, the CRISM spectrometer—onboard a spacecraft in Martian orbit—captured a sequence of characteristic bands between 1.4 and 2.8 microns.
In Aram Chaos, the measurements showed greater purity and coincided with the presence of sulfates such as kieserite and szomolnokite. In contrast, in Juventae, the signal was mixed with polyhydrated compounds, which suggests different thermal histories in each region.
Heat, water, and oxidation: the keys to the discovery
To confirm the origin of the mineral, the researchers recreated in the laboratory the conditions of early Mars. By heating hydrated ferrous sulfates between 100 and 300 °C (212 and 572 °F), they managed to reproduce the same light peak observed on the Red Planet.
