One day I got the idea to name the rest of the planets in the system Mobius inhabits, because there's bound to be other celestial bodies there. All of their names are references to geometry, since the name of Mobius itself was (sorta) derived from the strip.
* Guass is insanely hot, as to be expected from the first planet from the sun. Its core seems to be comprised primarily of iron.
* Darboux purees visitors on glass tornadoes that come and go with little warning. Observation is possible only with titanium-plated satellites, and even then, it's only a 50/50 chance that you'd be able to get all the data you were after.
* Geodesia might be habitable, but there's an aggressive Lesser Titan camped out on it and they're not fond of nosy mortals. On the one occasion they permitted an expedition, Geodesia was noted to be almost completely covered in colossal plant life and intricate rock formations.
* Parabolus seems to be inhabited, in that the people sent the Mobian UN a note requesting not to be bothered. All data is based on the last satellite sent there before then.
* Riemann is home to a massive ocean; what kind of liquid is actually in it has yet to be determined, but it doesn't seem to be water.
* Scalar's "main body" is essentially miles of dirt broken up by long stretches of brittle ground, one step onto which puts you at risk of falling to your death. The outer layers are much less arid.
* Yamabe is 99% posion by volume, and a favoured hang-out spot of Lesser Titans due to its remote and inhospitable nature.
* Bianchi is the planet from which light cannot escape--or maybe it's an illusion cast by a reclusive Dark Titan? Either way, study of the planet is extremely difficult.
* Frenet and Serret are double planets, and the farthest from the Sun. Both planets seem to be covered in thick layers of ice, with the different colourations resulting from the materials trapped in them.