Thanks to the combination of data sent by the Cassini spacecraft and the Hubble Space Telescope, astronomers were able to study this mysterious phenomenon.
Saturn’s north pole is a peculiar place where some clouds on the planet organize themselves in a hexagonal pattern. Recently, a team from the University of the Basque Country, in Spain, began to unravel some of the mysteries surrounding the phenomenon. They were able to do this thanks to the combination of data sent by the Cassini spacecraft and the Hubble Space Telescope.
Astronomers published an article about the study in the journal Nature Communications in early May. According to them, the cloud layer that forms the hexagon is 130 kilometers (80 miles) thick and is made up of tiny particles – possibly hydrocarbon ice.
“The Cassini images have enabled us to discover that, just as if a sandwich had been formed, the hexagon has a multi-layered system of at least seven mists that extend from the summit of its clouds to an altitude of more than 300 km above them,” said research leader Agustín Sánchez-Lavega in a statement.
The vertical extent of each layer is between 7 and 18 km (4 and 11 mi) thick, and their chemical composition is quite exotic. As the scientists explain, due to the low temperatures in Saturn’s atmosphere, which range between -120°C and -180°C, clouds may have hydrocarbon ice crystallites, such as acetylene, propyne, propane, diacetylene or even butane.
“Other cold worlds, such as Saturn’s satellite Titan or the dwarf planet Pluto, also have layers of hazes, but not in such numbers nor as regularly spaced out,” noted Sánchez-Lavega.
In addition, astronomers believe that the hexagon was formed due to the existence of gravity waves – a phenomenon formed by the interaction of a fluid with the force of gravity, like the waves of the ocean.
The team suggests that the differences in density and temperature and the dynamics between the hexagon and some jets emitted by the planet around the pole produce horizontal gravity waves that allow the vertical propagation of these gravity waves, forming the layers of clouds.