(internal structure of planets)
Planets have structure that can be modeled similar to
stellar structure. Some of the same equations are
appropriate and useful. Among the other factors:
- Trapped heat from planet formation can be a long-term factor.
- Radioactive heating can be an energy source.
- Absorption of the host star's EMR is a factor, including the effect of the atmosphere on received EMR.
- Albedo is a factor.
- Its constitution depends upon the results of planet formation, e.g., the loss of lightweight molecules from the atmosphere.
Gas giants in some ways present a more star-like model but
have their own specific characteristics.