A 15-year-old mystery on Mars has been solved. A mysterious signal first detected in 2009 has finally been traced to an unexpected source: a previously unknown mineral. Scientists identified it as iron hydroxysulfate, a form of mineral that does not naturally occur on Earth. It only forms when iron sulfates are heated to over 212 degrees Fahrenheit under the influence of oxygen.
Mars: The New Findings
As Study Finds reported, the University of Massachusetts Amherst, together with international partners, discovered that the mineral is present on both the Juventae Plateau and in Aram Chaos. While its formation on the Juventae Plateau is linked to volcanic heat, findings in Aram Chaos suggest hydrothermal processes. This discovery proves that Mars remained geologically active for an extended period.
The researchers achieved this breakthrough by heating various iron sulfates in the lab. Under controlled conditions, the samples transformed into iron hydroxysulfate. This allowed them to generate the exact spectral signature observed in satellite measurements on Mars. Temperature was crucial; the transformation only began at around 212 degrees Fahrenheit, with lower temperatures yielding no results even after days.
Latest News
What This Means for Research
The study results clarify that geological processes on Mars were more complex than previously assumed. Volcanic activity, subsurface heat, and later water movements could have led to the formation of iron hydroxysulfate over millions of years. This shifts our understanding of the planet. It did not “freeze” as quickly as many previous models suggested, but remained active significantly longer.
Future missions will now investigate whether iron hydroxysulfate is also present in other regions of the Red Planet. Current evidence suggests that other sulfate-rich areas might contain similar deposits. Every new discovery provides valuable insights into the evolutionary history of Mars and brings us closer to answering how long it was truly geologically active.
Sources: Study Finds; “Characterization of ferric hydroxysulfate on Mars and implications of the geochemical environment supporting its formation” (Nature Communications, 2025)
This article was translated with the help of AI and carefully reviewed by our editorial team.