Wind as the Earth to evolve into planets like Venus. Additionally, planets with hotter lower atmospheres could accelerate the loss rate of hydrogen. Rather than air, the solar wind is a stream of charged particles—a plasma—ejected from the upper atmosphere of the sun at a rate of . It consists mostly of electrons and protons with energies of about 1 keV. The stream of particles varies in temperature and speed with the passage of time. These particles are able to escape the sun's gravity, in part because of the high temperature of the corona, but also because of high kinetic energy
Degree of ionization plasma is in a "Coulomb-collision dominated regime", i.e. when formula_9, which can correspond to a degree of ionization as low as 0.01%. A "partially" or "weakly ionized gas" means the plasma is not dominated by Coulomb collisions, i.e. when formula_10. A particular case of fully ionizes gases are very hot thermonuclear plasmas, such as plasmas artificially produced in nuclear explosions or naturally formed in our Sun and all stars in the universe. Stars contain largely hydrogen and helium gases, that are "fully ionized" into electrons, protons (H) and helium ions (He). Equations to characterize such very hot, fully ionized thermonuclear