Earth's orbit around the Sun undergo periodic Milankovitch cycles.

• Orbit eccentricity: the shape of Earth's orbit varies between round and elliptical every 100,000 years.

• Axial tilt: the angle of the tilt as the Earth spins on its axis varies between 22.1° and 24.5° every 41,000 years.

• Axial precession: the tilt of the Earth's axis of rotation "wobbles" in 360° cycles of 20,000 years.