Science News from research organizations Scientists may have discovered a brand-new mineral on Mars Researchers have identified an unusual iron sulfate on Mars that may represent a completely new mineral. Date: March 10, 2026 Source: SETI Institute Summary: Scientists studying Mars may have uncovered a brand-new mineral hidden in the planet’s ancient sulfate deposits. By combining laboratory experiments with orbital data, researchers identified an unusual iron sulfate—ferric hydroxysulfate—forming in layered deposits near the massive Valles Marineris canyon system. The mineral likely formed when sulfate-rich deposits left behind by ancient water were later heated by volcanic or geothermal activity, transforming their chemistry. Share: Facebook Twitter Pinterest LinkedIN Email FULL STORY Aram Chaos. Credit: NASA/JPL-Caltech/University of Arizona A new study published in Nature Communications reports the detection of an iron sulfate on Mars that may represent a previously unknown mineral. Sulfur is abundant on Mars and commonly combines with other elements to create sulfate minerals. On Earth, most sulfates dissolve easily in rainwater. Mars, however, is extremely dry, allowing these minerals to persist for billions of years and preserve evidence of ancient environmental conditions. Each mineral has its own crystal structure and physical properties. Familiar examples include gypsum and hematite. Scientists analyze data from orbiting spacecraft to identify minerals on the Martian surface and reconstruct the environmental conditions that produced them. For nearly two decades, researchers have been puzzled by layered iron sulfates on Mars that show unusual spectral signals. A new investigation led by Dr. Janice Bishop, senior research scientist at the SETI Institute and NASA's Ames Research Center in California's Silicon Valley, has now identified and characterized an uncommon ferric hydroxysulfate phase. The team combined laboratory experiments with orbital observations of Mars to better understand these materials. Their results provide new clues about the roles of heat, water, and chemical reactions in shaping the Martian landscape. "We investigated two sulfate-bearing sites near the vast Valles Marineris canyon system that included mysterious spectral bands seen from orbital data, as well as layered sulfates and intriguing geology," said Bishop. Study Sites Near Valles Marineris The research focused on two areas close to Valles Marineris, one of the largest canyon systems in the solar system. One location is Aram Chaos, situated northeast of the canyon system where ancient water once flowed toward lower terrain to the north. The second site lies on the plateau above Juventae Chasma, a 5-km-deep canyon located just north of Valles Marineris. Juventae Plateau (above Juventae Chasma) This region near the cliffs of Valles Marineris preserves signs of a wetter past. Ancient channels carved by flowing water cross the landscape. Scientists found sulfate minerals concentrated in a small low area that likely formed when pools of sulfate-rich water gradually evaporated. As the water disappeared, hydrated ferrous sulfates were left behind. These minerals, including ferric hydroxysulfate, occur in thin layers roughly a meter thick that sit both above and below basaltic materials. Their position suggests they were later exposed to heat from lava or volcanic ash after they originally formed. "Investigation of the morphologies and stratigraphies of these four compositional units allowed us to determine the age and formation relationships among the different units," said Dr. Catherine Weitz, a co-author on the study and Senior Scientist at the Planetary Science Institute. Evidence From Aram Chaos Sulfate minerals are widespread throughout the Valles Marineris region, especially in rugged landscapes called chaotic terrains. Scientists believe these areas formed when massive floods reshaped the surface long ago. As the water evaporated, it left layered deposits of iron and magnesium sulfates that provide evidence of a much wetter Mars in the past. In one chaos terrain that formed within an ancient impact crater, the uppermost layers contain polyhydrated sulfates. Beneath them lie layers of monohydrated sulfates and ferric hydroxysulfate. How Heat Transformed Martian Sulfates Each of these sulfate types has a unique spectral signature that can be detected from orbit using the CRISM instrument. At first, the arrangement of these mineral layers was difficult to explain. Laboratory experiments helped solve the puzzle. Researchers found that heating polyhydrated sulfates to 50°C converts them into monohydrated forms. When temperatures exceed 100°C, ferric hydroxysulfate forms. These results indicate that geothermal heat likely altered the minerals after they were deposited. Polyhydrated and monohydrated sulfates appear across large areas of the region. Ferric hydroxysulfate is much rarer and occurs only