An Etymological Dictionary of Astronomy and Astrophysics

An → atmospheric escape that occurs when irradiation from a parent star (or a very high heat flux from a planet interior) heats a planetary atmosphere, causing its molecules to escape to space.

In basic models, the theory assumes neutral species with a → Maxwell-Boltzmann distribution of velocities, which occurs when collisions between molecules are frequent.

Thermal escape has two types: → Jeans’ escape and → hydrodynamic escape

(see, e.g., Catling, D. C. and Kasting, J. F., 2017, Escape of Atmospheres to

Space, pp. 129-167. Cambridge University Press).

See also: → thermal; → escape.