Transcript: For most planets in the solar system the orbital inclination is very small. That is, the axis defined by the north and south poles of the planet is almost exactly perpendicular to the plane of the planet’s orbit of the Sun. The only two exceptions to this are the Earth and Uranus. In the case of the Earth, the orbital axis is tilted by twenty-three and a half degrees, giving Earth its seasons. In the case of Uranus the tilt is even more extreme, more than ninety degrees, so Uranus is tilted almost on its side as it orbits the sun. The causes of these tilts for two of the planets in the solar system are almost certainly collisions with large bodies early in the history of the solar system. In the case of the Earth it was probably the collision that lead to the formation of the Moon.