Mildly interesting

Uranus moves much differently than the other planets in our Solar System, spinning on its side in comparison to the rest of the worlds in our neighborhood. Astronomers have often wondered just how this happened, but simulations performed by scientists at Durham University’s Institute for Computational Cosmology might have finally produced the answer.

“We ran more than 50 different impact scenarios using a high-powered super computer to see if we could recreate the conditions that shaped the planet’s evolution,” lead author Jacob Kegerreis explains. “Our findings confirm that the most likely outcome was that the young Uranus was involved in a cataclysmic collision with an object twice the mass of Earth, if not larger, knocking it on to its side and setting in process the events that helped create the planet we see today.”

Something absolutely huge slammed into Uranus when it was still young, causing it to tilt dramatically and spin on its side. The impact would have to have been a glancing blow, rather than a head-on collision, but the contact was sufficient to change the direction the planet’s axis is pointing.

http://icc.dur.ac.uk/giant_impacts/

Uranus is an odd planet. It spins on its side, with an obliquity of 98° and its major moons orbiting in the same tilted plane. This was most likely caused by a giant impact, which might also help explain other mysteries such as the planet’s extremely cold exterior and strange magnetic field.

We ran the first Uranus impact simulations since the original study in 1992 to study a wide variety of scenarios and the possible consequences of this violent event for the planet. As well as confirming that the impact could knock over Uranus’ spin, we found that with a grazing collision the impactor could form a thin shell around the planet’s ice layer, possibly preventing convection and trapping the interior heat to help explain the freezing outer temperatures.

George K · "Now look here, you Baltic gas passer... " - Mik, 6/14/08

https://solarsystem.nasa.gov/planets/uranus/in-depth/

Uranus is also one of just two planets that rotate in the opposite direction than most of the planets (Venus is the other one), from east to west.

Aqua Letifer

@George-K said in Mildly interesting:

https://solarsystem.nasa.gov/planets/uranus/in-depth/

Uranus is also one of just two planets that rotate in the opposite direction than most of the planets (Venus is the other one), from east to west.

That's why Venus' years are shorter than its days.

Klaus

@Aqua-Letifer said in Mildly interesting:

@George-K said in Mildly interesting:

https://solarsystem.nasa.gov/planets/uranus/in-depth/

Uranus is also one of just two planets that rotate in the opposite direction than most of the planets (Venus is the other one), from east to west.

That's why Venus' years are shorter than its days.

Why does that follow?

Aqua Letifer

@Klaus said in Mildly interesting:

@Aqua-Letifer said in Mildly interesting:

@George-K said in Mildly interesting:

https://solarsystem.nasa.gov/planets/uranus/in-depth/

Uranus is also one of just two planets that rotate in the opposite direction than most of the planets (Venus is the other one), from east to west.

That's why Venus' years are shorter than its days.

Why does that follow?

It doesn't have to, but the two are likely related. Something likely hit Venus back in the long ago to change its rotation. It's a theory supported by evidence but no it's not proven.