See our solar system’s planets spin. Though this 29-second video is short and silent, it’s an excellent animated example for observing the relative rotation periods of planets in 2-D. It also lists the length of each planet’s day along the right.
Fun fact: A day on Venus lasts 243 Earth days. A year on Venus lasts 225 Earth days.
In the above are sidereal (relative to the stars) rotation periods, and axial tilts of the planets were surgically removed. This animation below should answer a lot of Qs about tilts/directions of rotations (and hey it’s Pluto again!)…
Click on the animation below to see the tilts in action:
8 planets + 2 dwarf (for now) planets
Relative rotation rates and axial tilts shown. Tilts for each planet are found by the right-hand rule – close your hand, keep thumb out: rotation direction is given by fingers, while thumb points north. 10 hours passing each second. pic.twitter.com/pBxA91dLeP
— Dr James O'Donoghue (@physicsJ) February 26, 2020
Why do the gas planets rotate so quickly? Donoghue:
The planets spin because they picked up material that was already moving, and angular momentum must be conserved. At the same time, the bigger things are, the more material they must have accreted in the early stages of the solar system. So bigger usually means fast.
Why is Uranus spinning the other direction? A possibility:
This mind-blowing simulation by Jacob Kegerreis (of @durham_uni) shows how an ancient, giant impact of Uranus could've led its 98° tilt & wildly mixed up interior structure. As perhaps the least understood planet, it needs a mission! Let's support @IcyGiants #IceGiants2020 🚀 pic.twitter.com/U7Wo3SVpTE
— Dr James O'Donoghue (@physicsJ) January 22, 2020
Related reading: Why Venus Spins the Wrong Way.