The reasoning on this guy's website is often pretty fascinating: http://www.worlddreambank.org/P/PLANETS.HTM http://www.worlddreambank.org/P/PLANETS.HTM -- thes

The reasoning on this guy's website is often pretty fascinating: http://www.worlddreambank.org/P/PLANETS.HTM http://www.worlddreambank.org/P/PLANETS.HTM -- these are entire fantasy planets. For a warm-up exercise, he started out by tilting the Earth in different ways and working out how that would affect climate and biomes.