Uranus spins on its side. Uranus has an obliquity (tilt) of 98º, making its axis of rotation closer to the ecliptic plane than any other planet. It is not known how it got this peculiar tilt.
Table of Contents
- Uranus has an obliquity (tilt) of 98º, making its axis of rotation closer to the ecliptic plane than any other planet.
- Conventional wisdom over many years has been that one or more giant impacts must have turned Uranus onto its side when it was very young and giant impacts were common.
- Scientists propose a different way to tilt Uranus: spin–orbit resonance caused by a massive circumplanetary disk.
- Spin–orbit resonance is a type of secular resonance, meaning the precession of Uranus’ spin axis resonates with Uranus’ orbit.
- As the ice giants formed, they each had a circumplanetary disk which only lasts for ~ 1 million years before the material either falls into the planet or forms a moon.
- Scientists built computer models to capture the physical interactions of the disk and the planet and found that model 3 is the most realistic, supporting the hypothesis that spin–orbit resonance could be responsible for the high obliquity of Uranus.
A Nuclear Fusion Physicist and Astrophysicist.
BSc Physics & Engineering, MSc Nuclear Physics & Engineering, MSc Astrophysics, PhD Plasma Physics