Mars' Red Hue Linked to Watery Past

A recent study published in Nature Communications proposes that the iron mineral ferrihydrite is a major contributor to Mars' distinctive red color.

Researchers from Brown University and the University of Bern analyzed data from Martian orbiters, rovers, and laboratory simulations, finding that ferrihydrite, which forms in water-rich environments, is likely widespread in Martian dust and rock formations.

This contrasts with the previous theory attributing the color to hematite, a rust-like mineral formed in drier conditions. The discovery suggests that Mars may have once had a wetter, more habitable environment, as ferrihydrite requires cool water to form.

Scientists analyzed data from NASA's Mars Reconnaissance Orbiter, the European Space Agency's Mars Express and Trace Gas Orbiter, and rovers like Curiosity, Pathfinder, and Opportunity. The findings are awaiting confirmation through the return of Martian samples to Earth.