If it resided in our solar system, the greatest planetary ring system we’ve discovered would dominate the sky.
To put this ring system into perspective, if Saturn possessed the same rings, they would be several times greater in diameter than the moon in the night sky. It would not only be visible with the naked eye, but it would completely dominate the view. Overall, the exoplanet has over 30 layers of rings.
Artistic rendering of the exoplanet and its impressive rings. Image via Wikimedia.
“It’d be huge. You’d see the rings and the gaps in the rings quite easily from Earth,” said Matthew Kenworthy of the Leiden Observatory in the Netherlands, one of the co-authors on the paper describing the findings, at the time. “It’d be several times the size of the full moon.”
If the enormous ring system around J1407b’s replaced the rings of Saturn in our solar system, they’d be visible at night to the unaided eye, with many times the diameter of a full moon. Illustration via M. Kenworthy/Leiden.
Maybe the size of its rings helped too because J1407b was the first confirmed case of an exoplanet with a ring system. So far, it’s also the only exoplanet with rings that we’ve spotted.
Still, in cosmological terms, such lush manes of rings do not last for long. Researchers expect them to get progressively thinner and disappear in the next several million years as new moons form from the sheer quantity of material zipping and zapping through J1407b’s rings. Compared to planets in our solar system, J1407b is also very young, at only about 16 million years old. The Sun and Earth are 4.5 billion years old.
Artist’s concept of the ring system around the young giant planet or brown dwarf J1407b. Image via Ron Miller
So it might be just youthful energy that makes large ring systems possible. Right now, we simply don’t know. The methods we use to spot exoplanets (planets outside our solar system) aren’t very good at all at picking up ring systems — they can do it, but there’s a lot of luck involved.
For now, our best knowledge of planetary ring systems come from our neighboring planets. There may well be larger rings than those boasted by J1407b out there, but until we can get a better view into deep space — or, even better, make our way there — they will likely remain undiscovered.