A brief selection of problems occurring in the interpretation of planetary atmospheres, the resolution of which demands a knowledge of atomic collision processes, is presented. The selection is largely arbitrary.

Experimental data on electron scattering, optical refractivity, and molecular anisotropy are used to construct a model dipole spectrum for molecular hydrogen which is consistent with oscillator‐strength sum rules. The model ...

Theoretical studies of atom-atom collision processes which may be relevant to the interpretation of astrophysical phenomena are reviewed. Work on excitation, ionization, and electron capture in atomic hydrogen by fast ...