Perseverance, continuing its route along the ancient river valley in the crater of Ezero on Mars, in July 2024 drilled striped stone on the site a chavee waterfall and drew a sample named after sapphire canyon. These devices of the rover showed an unusual spotted pattern of two iron-containing minerals – vivianite (iron phosphate) and graigite (iron sulfide) on the rock surface. Both on Earth are often associated with life: Vyvianit is formed in environments with a large number of decaying organics, and Graigite can produce microbes using sulfates as a source of energy.
Researchers note that “leopard spots” are the fronts of chemical reactions – the zone where the substances are sequentially oxidized and restored. Such gradients can occur without biology, but on Earth they are often “pushed” by microorganisms that receive energy from these processes. In the case of Sapphire Canyon, the team did not find signs of high temperatures or strong acidity, which are usually required for abiogenic formation of vivianite and graigite. This strengthens the biological interpretation, but does not make it final.
On September 10, 2025, a study came out in which these structures are called potential Biosignature – not yet evidence that microbial life could exist on Mars. Scientists emphasize that the same minerals can form in a purely chemical way under certain conditions, without the participation of living organisms. Therefore, non-organic scenarios are also being considered at the same time.
Interest in finding, its age is also strengthened: it is one of the most “young” sedimentary rocks that the Rover studied. It was previously assumed that possible traces of ancient life should be sought primarily in older Martian deposits. If the hypothesis is confirmed, the window of potential inhabitability of Mars will be wider than previously thought – life could have lasted longer.
Further steps are obvious. For a final response about the origin of these minerals, the sample must be delivered to Earth: only laboratory methods, including accurate isotopic measurements and analysis of ultra-thin textures, will distinguish between biogenic and abiogenic signatures. In the meantime, scientists