– why does Venus spin in a different direction than the other planets in our solar system?

Question

From what I just read, Venus spins clockwise while the other planets spin counterclockwise. Why is this?

In: 447

Answer 1

I think the going theory is that Venus collided with another planet (proto) in the past.

If hit, then it either caused the rotation in the other direction, or it flipped Venus upside down.