This could explain the Mars methane mystery. https://www.nasa.gov/feature/goddard/2021/first-you-see-it-then-you-don-t-scientists-closer-to-explaining-mars-met

This could explain the Mars methane mystery. https://www.nasa.gov/feature/goddard/2021/first-you-see-it-then-you-don-t-scientists-closer-to-explaining-mars-methane-mystery https://www.nasa.gov/feature/goddard/2021/first-you-see-it-t... https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Exploration/ExoMars/The_methane_mystery https://www.esa.int/Science_Exploration/Human_and_Robotic_Ex... >Methane on Mars is expected to have a rather short lifetime – around 400 years – because it is broken down by ultraviolet light. Atmospheric mixing (for example, by winds) should quickly lead to a more or less uniform background concentration. But previous observations hint at seasonal variations in methane abundance, with concentrations varying with location and time. If this is correct, there must be an active source to replenish the supply and, at the same time, a relatively quick way of removing it in order to account for the apparent rise and fall in the measurements.