The Seasons
Science: KS3, topic 3.6.6
Seasons
The Earth is tilted at an angle of 23.5 degrees. It is because of this tilt that we have four seasons: winter, spring, summer and the autumn.
The Earth's axis
- The Earth rotates on its axis.
- It is believed the reason the Earth is tilted is because when the Earth was forming, a massive rock hit it and knocked it over slightly.
- After the collision, a chunk of Earth was flung into space - this ‘chunk’ is what we now call the Moon.
- The Earth’s axis always points in the same direction as the Earth orbits the Sun.
- Because of the tilt, the Sun appears higher in the night sky in the summer.
Hemispheres
- The equator is an imaginary line around the middle of the Earth.
- The equator is roughly 40,000km in length (about 25,000 miles).
- Day and night at the equator are an equal length.
- The half of the Earth above the equator line is called the Northern Hemisphere.
- The half of the Earth below the equator line is called the Southern Hemisphere.
Seasons
- People are wrong when they claim it is hotter in the summer because the Earth is closer to the Sun.
- When the tilt of the Earth is facing the Sun, it is summer in the Northern Hemisphere and winter in the Southern Hemisphere.
- The summer solstice is the longest day of the year. This is when the North Pole is tilted towards the Sun.
- When the tilt faces away from the Sun it is winter in the Northern Hemisphere and summer in the Southern Hemisphere.
- The winter solstice is the shortest day of the year. This is when the South Pole is tilted towards the Sun.
Test yourself on The Seasons
Why is the Earth tilted on its axis?
Which statement about the seasons is true?
Which fact explains why summer is not caused by the Earth being closer to the Sun?
What is the link between the collision that tilted the Earth and the Moon?