byDr. Christopher D. Impey, Professor of Astronomy, University of Arizona
Transcript: The composition of the atmosphere of any planet depends on three things. The first is the chemical composition of the material available to form an atmosphere. This is the original hydrogen and helium of the solar nebula plus trace elements combined with the amount of gas that outgases from the interior of the planet though it evolution. Second is the mass of the planet which dictates its surface gravity, and third is the temperature of the planet determined by its distance from the...