Nitrogen sulfide

Nitrogen sulfide (S4N4) was an inorganic compound that could be found in planetary atmospheres.

An inhabited planet located a few light years from Qo'noS (or Klingon space) had an atmosphere consisting of nitrogen sulfide. Following their mission that left them departing Qo'noS in 2151, the crew of Enterprise planned to visit the planet to begin their mission of exploration, with the expectations of finding non-humanoid life.