LONDON  -   We're looking at Saturn at a very special time in the history of the Solar System, according to scientists. They've confirmed the planet's iconic rings are very young - no more than 100 million years old, when dinosaurs still walked the Earth.

The insight comes from the final measurements acquired by the American Cassini probe. The satellite sent back its last data just before diving to destruction in the giant world's atmosphere in 2017. "Previous estimates of the age of Saturn's rings required a lot of modelling and were far more uncertain. But we now have direct measurements that allows us to constrain the age very well," Luciano Iess from Sapienza University of Rome, Italy, told BBC News.

The professor's team has published an account of its work with Cassini in Science magazine. There has long been a debate about the age of Saturn's rings. Some had argued these gorgeous loops of icy particles most likely formed along with the planet itself, some 4.5 billion years ago. Others had suggested they were a recent phenomenon - perhaps the crushed up remains of a moon or a passing comet that was involved in a collision. The US-European Cassini mission promised to resolve the argument in its last months at the gas giant.

The satellite's end days saw it fly repeatedly through the gap between the rings and the planet's cloud tops. These man oeuvres made possible unprecedented gravity measurements.

Cassini essentially weighed the rings, and found their mass to be 20 times smaller than previous estimates: something on the order of 15,400,000,000,000,000 tonnes, or about two-fifths the mass of Mimas - the Saturn moon that looks like the "Death Star" weapon in the Star Wars movies.