Years and seasons

A planet's year is the time it takes to make one complete orbit around the Sun. The Earth goes once round the Sun in one Earth year, which takes 365 Earth days.

Seasons

The Earth's axis is the imaginary line through the centre of the Earth between the South and North poles about which the Earth rotates. This axis is tilted slightly compared with the way the Earth orbits the Sun.

The Earth's axis is tiltedThe Earth’s axis is tilted 23.4° from vertical

We get different seasons (winter, spring, summer and autumn) because the Earth’s axis is tilted. This is how it works:

  • it is summer in the UK when the Northern Hemisphere is tilted towards the Sun
  • it is winter in the UK when the northern hemisphere is tilted away from the Sun
Shows the position of the earth in relation to the sun in different seasons. The northern hemisphere is tilted towards the sun in summer. In winter, the notheern hemisphere is tilted away from the sun.When it is summer in the Northern Hemisphere, it is winter in the Southern Hemisphere