Saturn’s rings are the most recognizable rings in the solar system. They are made of particles of many sizes, including dust, ice, and water. But scientists have always wondered about one question: When did they form?
In 1997, scientists at NASA sent the Cassini spacecraft to study Saturn’s rings and moons. Cassini took pictures of the rings and moons and sent them back to Earth. Cassini’s observations led to experts estimating Saturn’s rings to be around 400 million years old. This is because the experts did not see any impacts of micrometeoroids — space rocks smaller than sand — which would identify that it came from the early solar system, because they were prevalent at the time.
A new study from Japanese scientists at the Institute of Science Tokyo argue that the rings are much older than we think. They believe that the rings aren’t just millions of years old, but could be billions. They showed that any micrometeoroids would become gas or small drops of liquid when they landed, leaving barely any evidence of impact, meaning that the rings looked undamaged and much younger than they actually were .
We already know that Saturn is 4.5 billion years old — through radiometric dating — , around the same age as the rest of the solar system. The Japanese scientists used computer models to see how the rings first formed. They realized that the rings actually could have formed around the same time as Saturn. They thought that Saturn’s rings were in such good condition because it was incredibly resistant to pollution, not because they are young.
“Considering the solar system’s evolutionary history, it’s more likely that the rings formed closer to Saturn’s earliest times”, Hyodo, the organizer of the study, told the Associated Press in an email.