New simulations show possible reasons for Uranus' inclination

New simulations show possible reasons for Uranus' inclination

Researchers have developed a new theory to explain the strange inclination of Uranus and its clockwise rotation, based on the influence of its satellites.

A group of researchers from the University of Sorbonne, the University of Maryland, Park College, the University of Pisa and the University of Lazour Bank recently developed a new theory explaining the strange slope of Uranus and its clockwise rotation.

Uranium, the second-to-last planet of the solar system, is classified as an ice giant, third in diameter, and fourth in mass. It has a system of rings like Jupiter, Saturn and Neptune, although they are not very dense and therefore less visible. 27 satellites rotate on its equator. From the planets of our solar system, Uranus is one of the most interesting, mainly for two reasons:

  • The angle of its inclination to the orbital plane is 98°, which is much larger than any other planet.

Previous theories

In recent years, several theories have been developed to explain the unique characteristics of Uranus, one of the most widely accepted suggesting that a unique slope was caused by a collision with another large celestial body.

Japanese researchers at the Tokyo Institute of Technology in 2020 proposed a mathematical model that further explained this possible event, which would have been three times the size of the Earth's body, consisting entirely of ice, a collision, as well as the slope of the Uranu axis, would have led to the formation of a number of small satellites that are still orbiting the planet.

Another hypothesis over time suggests that the planet may have been affected by a group of smaller bodies; however, in both scenarios it was difficult to find concrete evidence of such events; however, researchers have now changed their perspective by taking into account the migration of ice giant satellites.

Impact of the Uranus satellites

A few years ago, researchers noticed that Jupiter's inclination was increasing because of the migration of his satellites, and mathematical calculations predict that his inclination would change dramatically over the next few billion years. When they looked at Saturn, they found similar results, mainly because of the migration of his largest satellite.

To test this hypothesis, researchers conducted several computer simulations, varying in the size and speed of the satellites, and the results confirmed their hypothesis: the body of even half the mass of the moon orbiting the Earth could gradually increase the rotation angle of Uranus to 90° for several million years.

However, researchers have noticed that the Uranu satellites around them do not have enough mass to create such inclinations; therefore, the Uranus satellite, large enough to affect the planet, should have existed in the past; indeed, modelling has shown that if a large satellite moves Uran's inclination to 80°, the situation will become unstable: the satellite will crash into the planet itself, with consequences similar to those of the collision theory.

At present, researchers believe that this could be a hypothesis that best explains Uranus's larger inclination than other planets and its clockwise rotation; it will be interesting to see in the future whether other studies will confirm or refute the results of this study.