Cozy space mystery set in Jupiter. The setting is interesting: humanity has fled a dying Earth and has build rings around Jupiter with interconnecting platforms. All transportation is made through rail cars that connects to stations.  A university professor mysteriously disappears: did he jump off the rings? Was it murder or suicide? It has Sherlock Holmes vibes with Investigator Mossa and her scholar girlfriend Pleiti. Intertwined with the mystery, there are discussions about ecosystem's equilibrium and the hope to transform Earth into a habitable place again. There is also some romance but it's very subtle. The language was a bit over the top to me, too formal. It made the dialogues seem unnatural. 
One thing bothered me: Jupiter is 10 times bigger than Earth in diameter, and building rings going around the whole planet seems....impractical? almost impossible? It wasn't clear if those rings were actually surrounding the whole circumference of the planet.