Titan: Aerosol photochemistry and variations related to the sunspot cycle

A photochemical theory is proposed for producing complex polymers in a methane atmosphere. It is argued that the polyacetylenes (C_(2n)H_2) are the most likely precursor molecules for the formation of the stratospheric haze layer on Titan. The production of polyacetylenes involves a strong positive feedback, leading to more production of polyactylenes. The thermosphere of Titan may undergo substantial expansion and contraction over a solar cycle, with important consequences for the chemistry of the upper atmosphere