Saturn's rings may have formed relatively recently. Researchers of a new study found evidence suggesting the planet's iconic feature could be very young, forming around 100 million years ago, at the time dinosaurs walked on Earth.
Cassini Mission
Luciano Iess, from Sapienza University of Rome, Italy, and colleagues used data from the Cassini mission to analyze Saturn's gravitational field and the mass of its rings. The two-decade-long mission studied planet Saturn, its satellites, and rings until it ended in September 2017.
Before Cassini spacecraft's fatal plunge into Saturn's atmosphere, it repeatedly flew through the gas giant's rings and its cloud tops.
The analysis of the data led to astronomical insights about the composition of the planet and the age of the rings.
"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," Iess said.
When Did Saturn's Rings Form?
The age of Saturn's rings has long been a subject of debate. Some researchers think these loops of icy particles may have likely formed along with the planet itself about 4.5 billion years ago. Some, however, argue the rings were relatively new, and these could be the crushed up remains of a moon or a planet that was involved in collision.
Data collected during Cassini's last maneuvers provided researchers more insights about Saturn's rings. Gravity measurements indicate the mass of these rings is 20 times smaller than previous estimates.
This information, along with the proportion of dust in the rings, and the rate at which this dust was being added, allowed scientists to work out the age of the planet's rings. They say it is just around 100 million years ago.
"The total mass of the rings is (1.54 ± 0.49)×1019 kg (0.41 ± 0.13 times that of the moon Mimas), indicating that the rings may have formed 107-108 years ago," the researchers wrote in their study, which was published in the journal Science on Jan. 17.
Collision Around The Age Of The Dinosaurs
The researchers said a big collision that occurred around the dinosaur age may have formed the rings of Saturn. This essentially occurred just yesterday relative to the full the age of the Solar System.
"Perhaps a big collision formed the rings around the age of the dinosaurs," Iess told Gizmodo.