When the Voyager probes first flew past Saturn decades ago, they discovered that the material that makes up the rings were raining down on the planet. The data from the probes were used to estimate a worst-case-scenario rate of destruction and new data has confirmed that it is indeed happening at that rate. The rings might be completely gone within 100 million years.
As reported in the journal Icarus, dusty ice crystals that make up the rings are being pulled in by the planet’s gravity. Some of these ice crystals are also being affected by Saturn’s strong magnetic field. The electrically charged pieces from the rings are following the invisible magnetic lines to deliver a large amount of water to the planet’s higher latitudes.
"We estimate that this 'ring rain' drains an amount of water products that could fill an Olympic-sized swimming pool" in half an hour, James O'Donoghue of NASA's Goddard Space Flight Center said in a statement. "From this alone, the entire ring system will be gone in 300 million years, but add to this the Cassini-spacecraft measured ring-material detected falling into Saturn's equator, and the rings have less than 100 million years to live. This is relatively short, compared to Saturn's age of over 4 billion years."
Saturn’s rings are mostly made of water ice pieces that can range from boulder-sized to microscopic grains. Due to the action of ultraviolet light from the Sun or plasma clouds produced by micrometeoroids hitting the rings, these ice chunks get electrically charged and begin to feel the action of the magnetic field. At this point, the forces acting on them are unbalanced and the ice crystals fly into the planet.
Recent studies have argued that complex ring systems like the one that Saturn sports are ephemeral structures, at least in cosmic terms. Scientists think that the rings are unlikely to be older than 100 million years, possibly formed from the collision between two icy moons.
"We are lucky to be around to see Saturn's ring system, which appears to be in the middle of its lifetime. However, if rings are temporary, perhaps we just missed out on seeing giant ring systems of Jupiter, Uranus and Neptune, which have only thin ringlets today!" O'Donoghue added.
While the future of Saturn's rings are uncertain and we are not sure how they came to be, we can at least keep enjoying this marvel of nature at the peak of its glory.