Hydrogen chloride discovery suggests Mars may still have volcanic activity
Researchers detected volcanic gas above fissures near Alba Mons, providing evidence of potential geological activity beneath the Martian surface.
An international team of researchers has detected hydrogen chloride in the atmosphere of Mars above narrow cracks on the northern flanks of Alba Mons, according to The Times of India.
The findings, which were published in Science Advances on November 4, 2026, were made using observations from the European-Russian ExoMars Trace Gas Orbiter.
Scientists identified unusual concentrations of the gas using infrared spectrometers. Further images from the spacecraft's CaSSIS camera showed surface fissures, some reaching hundreds of metres in length, alongside changes in surface colour.
Researchers suggest these fractures might act as pathways for gases escaping from an underground magmatic system. They noted that seasonal changes, such as winter ice melting or sublimating in early summer, might also affect these openings.
The discovery has implications for the search for life, as underground magma interacting with subsurface water could create hydrothermal environments. Such settings could provide the heat and chemical energy required for microorganisms to survive.
While the presence of the gas is consistent with volcanic processes, researchers stated it does not confirm an ongoing eruption or the existence of liquid water. Further observations are required to identify the gas source and determine if suitable underground conditions exist.