I’ve been putting together a talk about worldbuilding, distilling this whole series down into a couple of hours. As a handout I’ve created this chart, indexing planetary size against temperature to classify planets. It’s intended as a quick-and-dirty guide for people who don’t really want to go into the minutiae of planetary science. Anyway, here you go, the Planet Chart! (Click to see a bigger version.)

I color-coded some of the cells to highlight worlds which might have some form of native life. Green indicates Earth-type life (DNA and water-based). Pink is for ammonia-based life forms (DNA or equivalent and ammonia). Yellow is for silicon/sulfur-based life (some unknown complex silicon-carbon equivalent of DNA in molten sulfur or sulfuric acid). And blue is for hydrogen life (low-temperature molecules like DNA in liquid methane or liquid hydrogen).