Mud Kept Erupting in a Mars-Like Chamber Instead of Freezing Shut

In a chamber held at about the surface pressure of Mars, erupting mud kept itself going instead of freezing shut. Ondřej Krýza of the Institute of Geophysics of the Czech Academy of Sciences and colleagues report that rapid boiling, commonly assumed to quench such an eruption almost at once, is what sustained it.

The work is a laboratory reproduction of the process, not an observation of an eruption on Mars. The authors say it bears on sedimentary volcanism on Mars, which erupts mud rather than lava, and on ice eruptions on frozen moons. They say that how boiling, cooling and freezing act together to govern such an eruption has remained largely unknown. The paper appeared in Communications Earth & Environment on Oct. 21, 2026, open access under a CC BY license.

Krýza and colleagues held the chamber at about 4.5 millibars, near Martian surface pressure, and sealed the mud reservoir with ice so the eruption was driven by overpressure from its own boiling. Short-lived fountains threw mud clear of the vent first. The eruption then settled into pulses of outward flow, and mud that had landed near the vent pooled and merged into sustained flows even as it cooled and froze.

Numerical modeling in the same paper indicates that mud thrown from such a vent would stay largely unfrozen in flight under Martian gravity. The authors conclude that rapid boiling does not suppress this kind of volcanism at low pressure but instead sustains both the transport of the mud and its spread across the surface. They describe that as providing new constraints on the process on Mars, and as a broader physical framework for eruptions of liquids that cannot last at the surface elsewhere in the solar system.

The experiments used the Open University's Hyper Velocity Impact facility in Milton Keynes, UK, according to the paper's acknowledgments. A peer-review file is published alongside the paper, and the journal is serving the accepted version, which it says is subject to further edits before the final version of record replaces it.