What happens in the thermosphere and exosphere?

In the thermosphere, temperatures can rise significantly due to the absorption of high-energy solar radiation, leading to a region where the air is thin and temperatures can exceed 2,500°C (4,500°F). This layer is also where the auroras occur and where the International Space Station orbits. Above the thermosphere is the exosphere, which gradually transitions into outer space; it contains extremely low densities of hydrogen and helium atoms. The exosphere is where satellites orbit and is characterized by the free movement of particles, with some escaping into space.