Study of the Kinetics of Metastable Molecular Nitrogen in the Atmospheres of the Earth, Triton, Titan, and Pluto

Abstract

In the interaction of high-energy electrons with gases of planetary atmospheres where the primary component is molecular nitrogen, a significant fraction of particle energy is spent on the excitation of electronically excited triplet states of N2. The processes of energy transfer from metastable molecular nitrogen $${{{\text{N}}}_{{\text{2}}}}\left( {{{{\text{A}}}^{{\text{3}}}}\Sigma _{{\text{u}}}^{ + }} \right)$$ to other components in the atmosphere of the Earth (a mixture of N2–O2–O gases), as well as in the atmospheres of Titan, Triton, and Pluto (a mixture of N2–CH4–CO gases), are considered. The paper discusses the processes in which metastable molecular nitrogen $${{{\text{N}}}_{{\text{2}}}}\left( {{{{\text{A}}}^{{\text{3}}}}\Sigma _{{\text{u}}}^{ + }} \right)$$ affects the kinetics of electronically excited atomic and molecular oxygen in the auroral ionosphere of the Earth. In addition, it is shown numerically for the first time that the contribution of $${{{\text{N}}}_{{\text{2}}}}\left( {{{{\text{A}}}^{{\text{3}}}}\Sigma _{{\text{u}}}^{ + }} \right)$$ to the formation of electronically excited carbon monoxide CO(a3Π) increases significantly with increasing density in the atmospheres of Titan, Triton, and Pluto, and becomes predominant for the lower vibrational levels of CO(a3Π).