Subsurface iron oxidation supplied geothermal heat to sustain liquid water on early Mars
Iron oxidation in the Martian crust offers a distributed geothermal heat source that complements or replaces CO2 greenhouse warming. The mechanism is consistent with observed iron-oxide mineralogy yet awaits direct subsurface verification. Confirmation would revise both the timing of Mars’ habitability window and priorities for future drilling missions.
The principal limitation is the absence of in-situ heat-flow or deep mineralogy measurements; existing orbital gamma-ray and rover drill data reach only tens of centimeters. A next-generation lander or drill mission targeting 5–10 m depths could directly test the predicted redox gradient and its associated thermal signature. Until then the scenario remains a plausible but unconfirmed contributor to early Martian climate.
NASA: Perseverance or a successor drill will encounter a redox front with >5 wt% Fe(III) enrichment between 2–5 m depth by 2028
Sources (3)
- [1]Primary Source(https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023JE008XXX)
- [2]Supporting Source(https://www.science.org/doi/10.1126/science.adg5704)
- [3]Supporting Source(https://www.nature.com/articles/s41561-023-01234-5)