Figure 1-14The Tilt of Earth’s Axis Earth’s axis of rotation is tilted 23½° from being perpendicular to the plane of Earth’s orbit. Earth maintains this orientation (with its North Pole aimed at the north celestial pole near the star Polaris) throughout the year as it orbits the Sun. Consequently, the amount of solar illumination and the number of daylight hours at any location on Earth vary in a regular fashion with the seasons.