Venus: November 2019

A defining characteristic of the planet Venus is its thick, CO2-dominated atmosphere. Despite over fifty years of robotic exploration, including thirteen successful atmosphere probes and landers, our knowledge of N2, the second-most-abundant compound in the atmosphere, is highly uncertain (von Zahn et al., 1983).

The influence of the hydrogen hydrodynamic upper atmosphere escape, driven by the solar soft X-ray and extreme ultraviolet radiation (XUV) flux, on an expected magma ocean outgassed steam atmosphere of early Venus is studied.