4.5 billion years

How old are the rings of Saturn? According to a new study, led by Aurelien Crida of the Universite Cote d’Azur and the Institut Universitaire de France, they’re 4.5 billion years old — as old as the solar system itself.

The study found that the mass of the rings — 15.3 million billion metric tons — was consistent with being much older than the earlier estimated age of 100 million years. Determining the age of Saturn’s rings will help scientists figure out the age and evolution of the planet’s moons.

Abbi Matheson can be reached at abbi.matheson@globe.com. Follow her on Twitter @AbbiMatheson.