All the planets in our solar system rotate on their own axis, therefore having a North Pole and a South Pole, the points where the axis meets the planet's surface. Some planets, such as Mercury, Venus and Jupiter, have an almost perpendicular axis, with the consequence of not having any seasons.
Earth’s tilt at the present time is 23.5 degrees. This causes the sun to shine on different latitudes at different angles throughout the year, causing the seasons. When the North Pole tilts towards the sun, it’s summer in the Northern Hemisphere and vice-versa.
The axis of Uranus has the greatest tilt of all the planets in our solar system, near 98 degrees, so its North Pole is almost at its equator. This causes the most extreme seasons of all the planets, lasting 21 years, as for nearly a quarter of the Uranus year ( 84 earth years), the sun shines directly over one pole, leaving half the planet plunged into a long dark winter. Overall, it’s always cold.
If Earth were tilted like Uranus, spring and fall would receive relatively normal light, but in the summer in the Southern Hemisphere, the sun would never set, while the Northern Hemisphere would be plunged into darkness and cold. 188
The South Pole would melt completely, while the North Pole would freeze over, and the opposite 6 months later. These extremes at both ends of the planet would cause tremendously fierce and constant windstorms in the twilight zones. Oceans repeatedly freezing and thawing would greatly affect the planet, probably cooling it due to the greater albedo effect of ice.
Thank goodness Earth’s tilt is nowhere near that of Uranus! But why are the planets tilted differently and could this happen to Earth?
Scientists believe that Earth was struck by a large Mars-sized planet some 4.5 billion years ago, knocking off a big chunk which became the moon. The extreme tilt of Uranus was also caused by a great collision, but Earth’s moon saved it from being tilted as badly. The attraction of the Moon on the Earth keeps its axial precession, that is the variation of the angle of the axial tilt, between 22.1 and 24.5 degrees over a period of 41,000 years. This variation of the tilt has dramatic effects on Earth’s climate, but nowhere near what would happen if it were tilted like Uranus! 188