The Composition Of The Exosphere Is mainly atomic oxygen, hydrogen, helium and molecular state of nitrogen, oxygen.
The Exosphere is the outer layer of the top thermal layer (500 km) above the upper atmosphere region. Also known as the outer atmosphere, fugitive layer. The region free path of gas molecules in large, fast heat transfer for isothermal atmosphere. The atmosphere is extremely thin, they are not regarded as a continuous fluid, but the freedom movement of particles assemble them.