This paper by Carlson and Handel discusses observation of maser emission in planetary atmospheric plasma, presented at the 2nd International Symposium on Unconventional Plasmas. The work presents evidence for naturally-occurring maser (microwave amplification by stimulated emission of radiation) activity in planetary atmospheres including Earth, potentially explaining various electromagnetic phenomena such as radio emissions from Jupiter and Saturn, atmospheric glow discharges, and providing observational support for the maser-caviton theory of ball lightning.