Astronomers solve mystery of Jupiter’s missing rings

Jupiter should have enormous rings like Saturn, but its four major moons are stopping them from forming

Scientists have discovered why Jupiter does not have rings like its neighbouring gas giant Saturn.

Saturn’s rings are largely made of ice, some of which may have come from comets that are also made of ice.

“It’s long bothered me why Jupiter doesn’t have even more amazing rings that would put Saturn’s to shame,” said University of California, Riverside astrophysicist Stephen Kane.

“If Jupiter did have them, they’d appear even brighter to us, because the planet is so much closer than Saturn.”

The reason for Jupiter’s absent rings is relatively simple: its enormous moons prevent them from forming. The planet does in fact have smaller rings – as do Neptune and Uranus – but are not as substantial as Saturn’s and therefore are difficult to see with traditional stargazing equipment.

Researchers ran a computer simulation of both Jupiter’s orbits and the four main moons that surround it:  Io, Europa, Ganymede, and Callisto.

“We found that the Galilean moons of Jupiter, one of which is the largest moon in our solar system, would very quickly destroy any large rings that might form,” Professor Kane said. “Massive planets form massive moons, which prevents them from having substantial rings”. As such, it is unlikely that Jupiter ever had rings in its lifetime.

Jupiter’s rings are faintly visible in the recent images released by the James Webb Space Telescope, which has also revealed photos of the Carina and Southern Wheel nebulae, a collection of galaxies known as Stephen’s Quartet and a spectrum of light from the exoplanet WASP-96b.

“We didn’t know these ephemeral rings existed until the Voyager spacecraft went past because we couldn’t see them,” Professor Kane said, who next intends to simulate the conditions of Uranus for the same purpose.

Some astronomers believe that Uranus is tipped on its side as a result of a collision with another celestial body – and its rings could be the remnants of that impact.

“For us astronomers, [rings] are the blood spatter on the walls of a crime scene. When we look at the rings of giant planets, it’s evidence something catastrophic happened to put that material there,” Professor Kane said.

The results are soon to be published in the Planetary Science journal.