Overview
- The international study published Nov. 4 reports the ExoMars Trace Gas Orbiter measured repeated, localized spikes of hydrogen chloride above the flanks of Alba Mons that line up with newly imaged surface fissures, which the authors interpret as likely magmatic seepage.
- Researchers used TGO’s Atmospheric Chemistry Suite to detect the HCl and the CaSSIS, HiRISE and CTX cameras to image fresh, narrow cracks and nearby color changes on the same slopes, linking atmospheric chemistry with surface features.
- The team proposes a seasonal freeze‑seal and sublimation mechanism in which ice blocks fissures in winter and trapped magmatic gases escape in early northern summer, and they estimate low seepage rates of up to about 3 kilograms per second under their assumptions.
- No active eruptions, new lava flows or clear thermal hot spots have been observed, so the volcanic interpretation rests on correlated atmospheric and imagery evidence and requires additional, independent confirmation.
- If confirmed, the signals would add to prior signs of recent Martian geologic activity such as young lava flows and marsquakes and would make the Alba Mons fissures high‑priority targets for follow‑up orbital monitoring, seismic surveys and eventual in‑situ astrobiology exploration.