NASA's Cassini spacecraft discovered that Saturn's jet streams cross-cut rather than run parallel to its bands. This discovery was puzzling, as all other banded, rapidly rotating planets exhibit jet streams that are parallel to their bands.

A new study in the journal Nature Geoscience demonstrates why Saturn's jet streams do not behave the same as its fellow planets.

The study, led by scientists from the University of California, Berkeley and the University of Leicester, used computer models to simulate Saturn's atmospheric circulation and study the effects of the depths and heights at which the energy from the Sun is absorbed. The models showed that the absorption of solar radiation deep beneath Saturn's atmosphere, in addition to at the surface, has a significant influence on the planet's jet streams.

By comparing their model simulations to images of Saturn's clouds, the researchers were able to locate this deep energy absorption. They found that there are belts of clouds that are opaque to visible light at depths far beneath the main visible cloud deck, and that these opaque cloud decks absorb significant amounts of solar energy.

The deep absorption of solar radiation creates an atmospheric structure different than the other banded, rapidly rotating planets, which in turn causes the jet streams to cross-cut rather than run parallel to the bands.

This discovery has important implications for our understanding of the weather on Saturn and other banded, rapidly rotating planets, and could have implications for the climates of terrestrial planets like Earth.