Answer:
The air particles in the thermosphere absorb high-energy radiation from the Sun.
Step-by-step explanation:
The thermosphere lies above the mesosphere but below the exosphere in the Earth's atmosphere. The thermosphere can be considered to be part of space because of how close to space it lies, and ionization of particles by ultraviolet rays occurs a lot here; this been that some part of the thermosphere is overlapped by the ionosphere. Due to its proximity to space, particles in the thermosphere are exposed to a high level of solar energy radiation, which causes their temperature to be very high, sometimes as high as 1700 °C or more.