Frictional electrification is a common process in the Solar System, with Martian dust activities known to be a powerful source of electrical charge buildup. Furthermore, the thin atmosphere on the Red Planet makes the breakdown of accumulated electrical fields, in form of electrostatic discharge, much easier to occur — a hundred times easier than on Earth. Electrostatic discharge generates a huge amount of energetic electrons that collide with Martian atmospheric molecules and generate free radicals. These free radicals react with the Martian chlorides to generate new species. In new research, planetary scientists found the yields of (per)chlorates, carbonates, and chlorine from the electrostatic discharge process, with the strength matching mid-strength Martian dust activity, are at per thousand or percent levels. Their findings suggest that Martian atmosphere-surface interaction in dust events is a major driving force for the global chlorine-cycle on Mars.
“Electrical discharge on Mars probably looks more like a faint glow,” said Professor Alian Wang, a planetary scientist at Washington University in St. Louis.
“It could be somewhat like the aurora in polar regions on Earth, where energetic electrons collide with dilute atmospheric species.”
Planetary scientists consider chlorine one of five elements that are mobile on Mars; the others are hydrogen, oxygen, carbon and sulfur.
This means chlorine, in different forms, moves back and forth between the surface and the atmosphere on Mars.
On the ground, chloride deposits are widespread; they likely formed in the early history of Mars as precipitated chloride salts from brine.
In their new study, Professor Wang and colleagues show that one particularly efficient way to move chlorine from the ground to the air on Mars is by way of reactions set off by electrical discharge generated in Martian dust activities.
The authors conducted a series of experiments that obtained high yields of chlorine gasses from…
Read the full article here