Whatever your favourite planet in our Solar System, no one can deny the beauty of Saturn's rings. A new NASA study, however, reveals that they are disappearing at a "frenetic" pace. The pieces of ice that make up the bulk of the rings are raining onto the planet under the combined influence of its magnetic field and gravity.
Discover our latest podcast
Saturn without rings?
The frozen fragments that gravitate around the planet are at a point of equilibrium between the attraction of the planet and their speed of movement, like our International Space Station. However, unlike the ISS, these particles can be ionized by certain cosmic rays in sufficient proportions to be irretrievably attracted to the magnetic field of Saturn.
Gravity then attracts them to the upper atmosphere of the planet, following the lines of the magnetic field. Once up there, these fragments vaporize and turn into a rain whose proportions had already been accurately estimated by the researchers, based on the data transmitted by Voyager 1 and 2. "We estimate that this rain of rings 'drains a quantity of water-based products, able to fill an Olympic pool in half an hour,'" says researcher James O'Donoghue, co-author of the study published in the journal Icarus.
"On this basis alone, the entire ring system will disappeared in 300 million years, but if we add the measurement made by the Cassini probe, of material coming from the rings that fall towards Saturn's equator, they'll have less than 100 million years to exist. This is relatively short, compared to the 4 billion years of the planet's existence."
Temporary rings
The new study supports the hypothesis that the planet acquired its rings after its formation, indicating that they are probably less than 100 million years old. They could be the remains of two icy moons that could have once orbited the planet. These could have been disturbed in their trajectory by the passage of an asteroid or a comet, resulting in their collision and their destruction.
"We are lucky to be alive to testify to the existence of Saturn's rings, but if they are temporary, it also means that we may have missed the opportunity to contemplate the ring systems from other giants like Jupiter, Uranus and Neptune, who have only rings at the present!" O'Donoghue concludes.
Check out the video above to find out more about this phenomenon!
