Through my astronomy interests, I found the Youtube channel of Moiya McTier. Moiya’s an astronomer and folklorist (what a great combination of disciplines!). She and a rotating group of subject-matter experts (political scientists, plate tectonics experts, cephalopod specialists, etc.) start with a general exoplanet type: Extreme seasons, tidally locked, no insolation at all, etc. The types they start with are based on the actual science; as we learn more about exoplanets, we realize how much weirder they are than we predicted a few decades ago. Then, Moiya and her guests work to build a nifty world and the beings that inhabit it.
The creations so far are quite delightful: Worlds with turtle-like beings who have pyrite shells, deep sea sentients who communicate via thermal dancing, and much more. Any of the sessions would certainly be great inspiration for an SF campaign. More importantly, though, they’re just wonderful worldbuilding. From what I’ve seen, Moiya and her guests don’t insist that there be a plot; they’re interested in enjoying the worldbuilding, as worldbuilding for its own sake.
It reminds me of the “Build a World” game I’ve played and run several times at conventions. The difference is, Moiya and her guests are much scientifically rigorous — while not losing any of the elegant intricacy or beautiful internal logic that “Build a World” usually has. And, really, their worlds are about as fun as the “Build a World” ones, too. Well worth enjoying.