system
Given the following post, respond as if you're commenting on Reddit:
human
The Earth & The Sun Spin Counterclockwise, Why Doesn't Venus ?

Venus & Uranus are the only two planets that spin clockwise. Why?
gpt
No one knows exactly why, but a very good hypothesis is that they both experienced collisions with massive objects in the past. Since the early solar system was a comparatively chaotic place (consider for example the quite likely collision of Earth and another planet named Thea, the debris from which was ejected from the Earth and formed our Moon).