I've had a look around the internet and the only real classification system for planets seems to be the one from Star Trek, which I don't want to use. The real groups that planets fall under seem to be messy and unordered and I don't like it.
I'm looking for a way of categorizing planets into various groups relevant to colonization and what you'd need to colonize them. Bonus points if you can come up with a classification system with an order that's independent of the symbols used to denote each category. Like how the OBAFGKM system for stars used to be in order before we learned more.
The basic idea so far is a classification with 5 letters each of which can have subscripts. A letter for size, a letter for its average temperature, a letter for atmospheric composition, a letter for lithospheric composition and a letter for miscellaneous dangers and boons (like a particularly heavy moon meaning that you're lighter in march than in January or something else extraneous). Each letter will have subscripts denoting things like temperature fluctuation, the most abundant elements and other slightly less important info.
The civilisation in question does have FTL capability and the distance to the planet doesn't need to be taken into account. My main questions are about what type of classifications are most important and can be broken down into a couple of smaller questions.
Would it be better to have a system of classification that used surface temperature (and its range of fluctuation)[Advantage: More directly useful information for colonists] or would it be better to base it on orbital characteristics (distance from star and eccentricity)[Advantage: The system of classification can be expanded to moons, asteroids, and comets.]?
Would it be more important to define a planet's size in terms of its mass or its volume?
What would be a good way to calculate a "Survivability Score" for the atmosphere and lithosphere based on the elements and proportions of elements? (Note: I reckon I'll be using a separate letter for lithospheric and atmospheric composition)
Rather than ask for the definition of planet types lets work on the creation of a system against which to judge and categorize planets in relation to how well they can be colonized.
- What are the 5 physical planetary characteristics most important in relation to colonization
- How can these factors be combined to create classes