A model of Martian surface chemistry

Area of Science:

• Planetary Science
• Astrobiology
• Geochemistry

Background:

• The Viking Biology Experiments revealed unusual reactivity in Martian surface samples.
• Previous explanations for these reactions remain incomplete.

Purpose of the Study:

• To propose a unifying hypothesis for the observed reactivity of Martian surface materials.
• To explain the chemical and thermal behaviors noted in the Viking experiments.

Main Methods:

• Chemical analysis of proposed Martian surface constituents.
• Thermodynamic and kinetic modeling of reactions involving proposed constituents.
• Correlation of proposed constituents with Viking experimental data.

Main Results:

• Alkaline earth/alkali metal superoxides/peroxides, gamma-Fe2O3, and carbon suboxide polymer are proposed Martian surface constituents.
• These substances explain water-modified reactions and thermal behaviors observed in Viking experiments.
• Electrical discharges between wind-mobilized particles at Martian pressures are proposed as the primary synthesis mechanism, creating reactive species via plasma.

Conclusions:

• The proposed reactive substances provide a consistent explanation for Viking Biology Experiments.
• Electrical discharges and plasma chemistry are key processes for generating reactive surface materials on Mars.
• This hypothesis offers a new perspective on Martian surface composition and its implications for astrobiology.