Saturn's Rings Actually Formed While Dinosaurs Roamed Earth, Scientists Say

Saturn's rings are much younger than we initially thought, with scientists saying that they may have formed when dinosaurs still roamed the Earth.

In a new study published in the journal Science, scientists analyzed data from NASA's Cassini spacecraft and found that Saturn's iconic rings may have only started existing between 10 million and 100 million years ago. Based on this timeframe, the rings could be much younger than the dinosaurs, who ruled the Earth for around 175 million years before they were wiped out about 66 million years ago.

Saturn's rings were initially believed to have formed with the planet itself about 4.5 billion years ago, perhaps as a result of the icy debris left in orbit around it during the early years of our solar system's formation. It was later discovered that Saturn's rings were younger than the planet, but scientists had never been able to determine how much younger they actually were.

So how were scientists finally able to determine the age of Saturn's rings? They used the data collected by the Cassini during its final orbits to measure one thing they needed to know, which was the mass of the rings or how much material they contain.

Before it was destroyed in September 2017, the Cassini spacecraft performed 22 dives between Saturn and its rings. While diving, the Cassini acted as a probe and fell into the planet's gravity field, letting the gravitational force tug it every which way.

The mission team was able to measure the gravity and mass of both Saturn and its rings by analyzing how much gravity was pulling the Cassini, since the strength of a body's gravity is dependent on its mass.

Luciano Iess, the study's lead author and Cassini radio science team member, and his colleagues built on the previous connection made by scientists that the lower the mass, the younger the rings' age would be. This is because the bright and icy rings would have been tainted by interplanetary debris over a longer period of time. Researchers were able to learn from data collected by a previous Cassini mission that the gas giant's rings are only around 1 percent impure.

With the use of this finding and the calculated weight of Saturn's rings, less and his team were able to determine how long it would take for the planet's rings to be contaminated enough to become 1 percent impure. This then led to them having enough data to calculate the age of the ring system.

"Only by getting so close to Saturn in Cassini's final orbits were we able to gather the measurements to make the new discoveries," the planetary scientist at Sapienza University of Rome said in a statement. "And with this work, Cassini fulfills a fundamental goal of its mission: not only to determine the mass of the rings, but to use the information to refine models and determine the age of the rings."

Saturn's rings were initially believed to have a mass of about 28 million billion metric tons, based on data from Voyager's flybys of the planet. The new study, however, determined that Saturn's rings' mass is actually only around 15.4 million billion metric tons.

The Saturn mission team will continue studying data about the planet to find out how the rings were actually formed. Saturn's rings being much younger than initially thought seemed to support the idea that the rings were the result of a comet that entered Saturn's gravitational field and was thus torn apart. It's also possible that the rings formed due to the icy moons breaking apart.