Praxis

Praxis is a Klingon moon orbiting Qo'noS. It was the key energy-production facility for the Klingon Empire until 2293. That year, a combination of mishaps occured, causing an explosion that disintegrated most of the moon - the disaster was later attributed to poor mining practices.

A subspace shock wave from the incident disrupted operations aboard starships, including a Starfleet ship, the Excelsior. The result of that explosion polluted the ozone layer of Qo'noS, leaving it with approximately 50 Earth standard years of life left. With the Klingon empire's economy and infrastructure in shambles, peace negotiations were established with the Federation that same year. This tenuous peace anticipated the later alliance between the Federation and Klingon empire.