Axis Tilt Definition |work| Page

It is a common pedagogical error to define axis tilt as "the angle of the Earth's axis from the vertical." While functionally equivalent, the precise astronomical definition references the orbital plane (the ecliptic). Thus, Earth’s axis is tilted 23.44° away from the perpendicular to its orbital path.

| Planet | Axis Tilt (Obliquity) | Notable Effect | | :--- | :--- | :--- | | Mercury | ~0.03° | No seasons | | Earth | | Temperate seasons | | Mars | 25.19° | Similar seasons, but more extreme due to eccentric orbit | | Jupiter | 3.13° | Negligible seasonal variation | | Saturn | 26.73° | Pronounced seasons (7+ years each) | | Uranus | 97.77° | Extreme seasons; poles face Sun directly | axis tilt definition

1. Formal Definition