The solar system has many unsolved mysteries, including the abnormally high temperature on the atmospheric surface of the gas giants. It seems that they are heated by a hot source other than the Sun. The mysterious heat source has been a hot discussion topic for astronomers.

Exploring Saturn for 13 years, the Cassini spacecraft crashed into Saturn's atmosphere in 2017, but it still collected data of Saturn's atmosphere during its last orbit to reveal the secret of the mysterious heat source. It was found that Saturn's atmosphere has the highest temperature near the poles, which are the places where Saturn's auroras appear. Astronomers believe that, Saturn's auroras and the induced electric currents heat its upper atmosphere, and the heat is carried to other area by the strong air flow, which accounts for the high temperature of Saturn's atmosphere.

By understanding more about the reaction between the solar wind and the gas giants, scientists could resolve the mystery so called "energy crisis" in the solar system and understand more about the exoplanets in the universe.