Uranus, the 7th planet from the Sun, is unique because it spins sideways! Most planets spin around an axis (invisible line that goes through a planet) that is vertical or stands straight up. Uranus’ axis is actually horizontal, meaning that it spins sideways. Scientists are still not sure why Uranus spins that way, but a theory is that a comet or asteroid may have struck Uranus and flipped it sideways. This is why Uranus spins sideways!