Definition: Exospheres are a type of atmospheric layer that is composed primarily of nitrogen oxides and sulfuric acid. They form when nitrogen oxides, which can be produced by burning fossil fuels, react with water vapor in the atmosphere to produce sulfur dioxide and nitric oxide. These gases then rise into the stratosphere where they become more concentrated due to the low pressure and temperature conditions. As these gases continue to rise, they begin to interact with the lower layers of the atmosphere, forming a layer