Earth Axis Inclination to Ecliptic Plane

The Earth's axis, the imaginary line about which the Earth rotates, is not perpendicular to its orbital plane. The orbital plane is known as the plane of the ecliptic.

The Earth's axis is tilted at an angle relative to the perpendicular line to the ecliptic plane. This tilt is approximately $23.5^\circ$ from the perpendicular.

To find the angle of inclination to the plane of the ecliptic itself, we subtract this value from $90^\circ$:

• Angle = $90^\circ - (\text{tilt from perpendicular})$
• Angle = $90^\circ - 23.5^\circ$
• Angle = $66.5^\circ$

This value, $66.5^\circ$, is equivalent to $66 \frac{1}{2}$ degrees.

Therefore, the axis of the Earth is inclined to the plane of ecliptic at an angle of $66 \frac{1}{2}$ degrees.