Planetary Electrochemical Effects

Lightning on a planet other than the Earth was first discovered by Voyager when it flew past Jupiter in 1979. Since then it has been reported on Saturn by Voyager and Cassini, and on Venus from Pioneer Venus and Venus Express. While lightning involves clouds formed from polar molecules such as water, or vulcanism, dusty environments often create electrostatic fields through triboelectric phenomena. In each instance, changes in local chemistry with profound global impact can occur, such as lightning-induced nitrogen fixation on earth. Perhaps the most dramatic effect occurs on Mars within its global dust storms and dust devils. Enhanced production of oxidants, such as hydrogen peroxide, sulfur and halogen species including perhaps perchlorates from minerals in airborne dust are some of the likely chemical effects. The oxidants may be responsible for the lack of organics on the surface of Mars and rapid destruction of methane in the atmosphere. On Titan, the surface organics may be altered by a different (charged particle) effect, a phenomena that may also operate in the polar regions of Mars and on the Galilean satellites. In this talk, we will discuss possible chemical and astrobiological implications of above electrical processes.