Saturn’s rings are one of the most beautiful sights in the solar system - thousands of glittering icy bands stretching almost 280,000 kilometres across, but in some places only the height of a tall building thick. For a long time, astronomers assumed the rings had been there as long as Saturn itself, more than four billion years.
Then in 2017, NASA’s Cassini spacecraft did something risky on purpose. At the end of its mission it dove between Saturn and its rings 22 times, letting the planet’s gravity tug on it. By measuring those tugs, scientists figured out how heavy the rings really are. The answer was surprisingly small. Combined with how clean and bright the ice still looks, that points to a much younger age - probably only around 100 million years.
That means when Tyrannosaurus rex was alive on Earth, Saturn had no rings at all. Some giant comet or moon was probably ripped apart in Saturn’s gravity not that long ago, and the shattered pieces are what we see today. Worse, the rings are slowly being pulled into Saturn’s atmosphere as a kind of ice-rain. In another 100 million years or so, our solar system’s most famous decoration will be gone.
