The Ice Giant Planet that Put Jupiter and Saturn in their Place
How did Jupiter and Saturn get where they are today? A massive ice giant planet which once orbited between Saturn and Uranus may have played a role in shaping our Solar System.
Did a massive ice giant planet once orbit in the outer solar system? And what could evidence for such a world teach us about the original positions of Jupiter and Saturn?
The ancient Solar System was the formed from a disk of gas and dust spiraling around the nascent Sun. At first, most astronomers believe, the earliest planets formed in regular, closely-packed, orbits. Soon, however, gravitational tugs from the most massive of these worlds played havoc with the regular orbits of their neighbors.
It was once thought that solar systems like our own — with small, rocky planets placed close to their parent star and larger gas giants in the outskirts of the system — would be common. But, following the discovery of 4,500 exoplanets, the makeup of our solar system was found to be rare.
“We now know that there are thousands of planetary systems in our Milky Way galaxy alone. But it turns out that the arrangement of planets in our own Solar System is highly unusual, so we are using models to reverse engineer and replicate its formative processes. This is a bit like trying to figure out what…
