Isotope effects (Cl, O, C) of heterogeneous electrochemistry induced by Martian dust activities

Journal article

Some oxidized compounds in Martian soils may form through heterogeneous electrochemistry (HEC) stimulated by electrostatic discharge (ESD) during dust storms and dust devils. To test this hypothesis, we conducted medium-strength ESD experiments in a Mars simulation chamber and analyzed the Cl, O, and C isotopic compositions of the resulting chloride, (per)chlorate, and carbonate products. These ESD products exhibit substantial mass-dependent depletions in heavy isotopes: ε 37Cl from -11.3 ‰ to +2.0 ‰, ε 18O from -34.5 ‰ to -12.9 ‰, and ε 13C around -11.4 ‰. These results, when compared with isotopic measurements from recent Mars missions (ESA’s ExoMars Trace Gas Orbiter and the Sample Analysis at Mars (SAM) instrument package aboard NASA’s Curiosity rover) and Martian meteorites, indicate that HEC induced by Martian dust activities can account for a substantial portion of the (per)chlorates and carbonates identified at the surface of Mars.

Authors: Sturchio, NC; Yan, H; Wang, A; Jackson, A; Bao, H

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Earth and Planetary Science Letters
• Volume: 676
• Article number: 119784
• Publication date: 2025-12-18
• Acceptance date: 2025-12-09
• DOI: 10.1016/j.epsl.2025.119784
• EISSN: 1385-013X
• ISSN: 0012-821X
• Language: English
• Keywords: Mars surface-atmosphere interactions; dust activity; electrostatic discharge; kinetic isotope effects; heterogeneous electrochemistry