Astronomers have discovered why the upper atmosphere of giant planets such as Saturn and Jupiter are hot, although they are much farther from the Sun than the Earth. The heat source was one of the great mysteries of the solar system, which for a long time remained unsolved. The discovery is reported by Phys.org.
This mechanism helps to solve the problem of why the upper part of the atmosphere is so hot and the rest of the air shell remains cold, as expected due to the remoteness of Saturn from the Sun.
The temperature of the upper layers was measured by observing the refraction of light from bright stars in the constellations Orion and Big Dog at the boundary of Saturn’s atmosphere during the flight of Cassini. This made it possible to know the density of the air envelope, which decreases with height, but the rate of decrease depends on temperature. It turned out that the temperature reaches a maximum near the auroras.