Axial tilt

From Wikipedia, the free encyclopedia

In astronomy, axial tilt is the angle between a planet's rotational axis at its north pole and a line perpendicular to the orbital plane of the Planet. It is also called axial inclination or obliquity. The axial tilt of Earth is the cause of seasons like summer and winter on Earth.

[change] Axial tilt of major celestial bodies in our solar system

Sun 7.25 (to the Ecliptic)

Mercury ~0.01

Venus 177.4

Earth 23.439281

Moon 1.5424

Mars 25.19

Ceres ~4

Jupiter 3.13

Saturn 26.73

Uranus 97.77

Neptune 28.32

Pluto 119.61

[change] Axial tilt of Venus, Uranus, Pluto

Axial tilt of Venus, Uranus and Pluto is greater than 90 degrees because of following reasons.

• Venus: Venus is rotating in retrograde direction, opposite to the direction of planets like Earth. North pole of Venus is pointed 'downward'(southward). Hence angle between rotational axis of Venus passing through north pole and the line perpendicular to orbital plane of Venus is 177.4 degrees.

• Uranus: Planet Uranus is rotating on its side. Direction of its rotational axis and north pole is almost in the direction of its orbit around Sun. Hence its axial tilt is 97.77 degrees. If the direction of rotational axis and north pole of Uranus had been aligned horizontal with its orbital plane and in the direction of orbit around the Sun then axial tilt of planet Uranus would have been perfectly 90 degrees.

• Pluto: Like Venus, rotational axis and north pole of Pluto is slighty pointed downward(southward). Hence angle between rotational axis of Pluto passing through north pole and the line perpendicular to orbital plane of Pluto is 119.61 degrees.^[1]

[change] References