Since I have learned about the current classification of exoplanets, that is used these times in sciences, I wondered if it is possible to compare it with the Federation classification of planets. The Sudarsky extrasolar planet classification is based on modeled physical properties of the planets’ atmospheres and can only be used for gas giants (see the small list below). This limits the comparison to the classes J and T, and the class 6, 7, and 9 gas giants in the Federation classification (the memory alpha article on that topic is a bit confusing).
Sadly there is not much information on composition or temperatures for gas giants in Star Trek. Examples for Class J planets are given by memory alpha as Jupiter and Saturn. Class T seems to be some kind of a “large ultragiant” (whatever that means). Class 6 gas giants have a layer of liquid hydrogen and methane. The only information on class 7 gas giants is that it is hard to distinguish visually from Class 6 gas giants and for class 9 gas giants we only know that we don’t have one in our solar system. That’s really not much information. Class I in the exoplanet classification and Class J are matching, because both classes give Jupiter and Saturn as examples, but that seems to be all. The layer of liquid hydrogen and methane found in Class 6 gas giants is probably something that is not unique to this class. We know that Jupiter and Saturn have layers of liquid metallic hydrogen, but they are already classified as Class J planets, so I thought about that the class 6, 7, and 9 gas giants (and probably at least classes 1-5) could be some kind of subclasses to Class J.
Has anyone more ideas on the comparison or more information on the planet classification used by the Federation, that could help? I just love comparing the science in Star Trek with what we have today. =)
Sudarsky extrasolar planet classification that is used to describe exoplanets:
The classification is based on models of the atmospheres of an exoplanet, including the temperature-pressure profile and composition.