Question

Why is Uranus sometimes called the sideways planet

Answer 1

Uranus is an oddball in that axis of spin is tilted by a whopping 98 degrees, meaning it essentially spins on this side.

Answer 2

Uranus is called the sideways planet because it rotates a different way than any of the other planets in the solar system. Uranus rotates on its side, perpendicular to the north-south orientation of Earth and other planets. For this reason, Uranus is sometimes called the sideways planet.