Astronomers have discovered that Saturn's ring system is heating the gas giant's upper atmosphere in a way never seen before in the solar system. The discovery is reported in an article published in The Planetary Science Journal.

The researchers analyzed data from the Hubble Space Telescope, the Cassini probe, the Voyager 1 and Voyager 2 spacecraft, and the International Ultraviolet Explorer space telescope. Scientists have identified an excess of ultraviolet radiation, which is observed in the form of a spectral line of hot hydrogen in the atmosphere of Saturn. This indicates an external influence that pollutes and heats the upper part of the atmosphere.

The most plausible explanation is that the heating is caused by icy particles in the rings that rain into Saturn's atmosphere. In addition, this "shower" can be associated with the impact of micrometeorites, bombardment by solar wind particles, ultraviolet radiation, or the action of electromagnetic forces that attract charged dust.

Four decades of UV data span several solar cycles and help astronomers study the Sun's seasonal impact on Saturn. By pulling together all the various data and calibrating them, the scientists found that there was no difference in the level of UV radiation. This makes it possible to reject the scenario in which the atmosphere is heated by solar energy and confirms the rain hypothesis.