Axial tilt
From the Simple English Wikipedia, the free encyclopedia that anyone can change
In astronomy, axial tilt is the inclination angle of a planet's rotational axis in relation to a 90 degree angle to its orbital plane. It is also called axial inclination or obliquity. The axial tilt is expressed as the angle made by the planet's axis and a line drawn through the planet's center perpendicular to the orbital plane.