After six seasons, “The Expanse” closes on its own terms…

*****CERES-SIZED SPOILERS!!***** After six seasons, or more like five and a half, Amazon Prime’s “The Expanse” has come to an end, though it leaves open opportunities for a potential comeback. The series is based on the novels by “James S.A. Corey” (noms de plume for authors Ty Franck & Daniel Abraham) and was adapted by…