Saturn's moons and rings may share age with dinosaurs

A new study suggests that the inner moons and rings of Saturn may have only recently formed during Earth's era of dinosaurs.
By Kathy Fey | Mar 26, 2016
Some of the moons and rings encircling Saturn may actually be younger than an age during which dinosaurs roamed the Earth.

According to, new computer models indicate that much of the Saturnian system could be less than 100 million years old. The model found that Saturn's moons Tethys, Dione and Rhea do not demonstrate the change in orbital tilt that would be expected of moons that had been under the influence of the rest of the system's gravitational influences for over 100 million years.

"Moons are always changing their orbits. That's inevitable," Matija Cuk of the SETI Institute said. "But that fact allows us to use computer simulations to tease out the history of Saturn's inner moons. Doing so, we find that they were most likely born during the most recent 2 percent of the planet's history."

The team used readings of geysers on Saturn's moon Enceladus to help determine the strength of Saturn's tidal forces, which would be an influencing factor in the orbits of its moons. Computer simulations helped the research team determine that Encedalus probably took 100 million years to settle into its current orbit, having formed during Earth's Cretaceous period.

The results indicate that Saturn's other inner moons and rings most likely formed in a similar time frame and are therefore relatively young.

"So the question arises what caused the recent birth of the inner moons?" Cuk said. "Our best guess is that Saturn had a similar collection of moons before, but their orbits were disturbed by a special kind of orbital resonance involving Saturn's motion around the sun. Eventually, the orbits of neighboring moons crossed, and these objects collided. From this rubble, the present set of moons and rings formed."

The study will appear in the Astrophysical Journal.


We are dedicated to maintaining a respectful community that actively engages in lively discussions about news stories and blog posts. Please keep the following in mind when writing your comments.