During the latest Starship mission, I noticed a curious orange ring around the engine plume: My first thought was: Color of nitrogen oxides but no nitrogen fuels High temperature exhaust plume Extreme plume shock waves Disappeared above 45 km, thiner atmosphere Google reports: Themal : The exhaust plumes of rocket engines (especially those burning kerosene, liquid hydrogen, or solid propellants) reach temperatures exceeding \(2000^{\circ }\text{C}\) to \(3600^{\circ }\text{C}\). At these extreme temperatures, atmospheric nitrogen (\(\text{N}_{2}\)) and oxygen (\(\text{O}_{2}\)) dissociate and recombine to form nitrogen monoxide (\(\text{NO}\)) and nitrogen dioxide (\(\text{NO}_{2}\)). [1, 2, 3] Bob Wilson
