JPL / Space Science Institute / NASA
The planet Saturn, seen by the Cassini spacecraft during the equinox. Data on how the rings cooled during this time provide information about the nature of the ring particles.
The thin thickness of the rings creates an optical illusion that makes it appear as if they have disappeared when facing Earth. The phenomenon happens every between 13.7 and 15.7 years.
Saturn, one of the most captivating planets in our Solar System, will be the protagonist of a rare astronomical spectacle in early 2025.
Known for its iconic rings of ice, dust and rock, the gas giant will align itself in such a way that its rings will seem to disappear when observed from Earth. This phenomenon, called “ring plane crossing”, happens when Saturn’s rings face our point of view, making them almost invisible due to their thin profile.
The event, scheduled for March 23, 2025occurs every 13.7 to 15.7 years, when Saturn completes its 29.4-year orbit around the Sun. The planet’s equatorial tilt of 26.7 degrees, combined with its seasonal changes, leads to this fascinating visual effect, says .
Although Saturn’s rings stretch an impressive 280,000 kilometers in diameter, their thickness measures just tens of meters, creating the illusion of disappearance when viewed from the front.
For astronomers and space enthusiasts, this rare alignment offers a preview of Saturn’s distant future. Recent studies suggest that the planet’s rings are not permanent. NASA’s Voyager mission revealed that ring particles are slowly falling towards Saturn, a process that could cause them to disappear within about 300 million years.
“We are lucky to be around to see Saturn’s ring system, which looks be in the middle of your life,” noted James O’Donoghue of NASA’s Goddard Space Flight Center. The temporary nature of Saturn’s rings also raises questions about the past of other gas giants such as Jupiter, Uranus and Neptune, which currently have only faint rings.
After the March 2025 event, ground-based observers will have a view of Saturn’s south pole and the underside of its rings, perspectives that have not been seen for many years.
