As nice as summer is, we really need the other seasons as
well.
Why do we have seasons?
We all know that the world turning makes day and night. In 24
hours the world turns round once. When we are facing the Sun
it is day. When we face away it is night. Simple!
We travel around the Sun in a circle, so why does it get colder
in the winter?
It's because the spin of the Earth is actually wonky. The axis
of the Earth is tilted, which means that in summer we (in the UK)
are leaning towards the Sun. As we travel around the Sun, we begin
to tilt away and it becomes winter.
Have a look at this clip to see how the Earth's tilt changes the
seasons.
This is why when we have winter, Australia has summer. Imagine
having Christmas dinner on the beach! But not all countries have
seasons. Countries near to the equator - the line which goes round
the middle of the earth - have very mild seasons. The weather stays
almost the same temperature all the year round.
Can you think why this is?
The middle doesn't tilt very much does it? This means the
seasons don't change as much.
Can you guess what the seasons are like in the North and South
Pole? Because they tip further towards and further away from the
sun, their seasons are very extreme. The North and South Pole only
have one sunrise and one sunset a year.
It is dark for six months of the year and light for six months of
the year.
What problems would there be if you had to live somewhere that
was dark for six months of the year and light for six months of the
year?
The sun seems to move across the sky during the day because the
Earth is spinning. The stars do exactly the same thing. They seem
to move a across the sky at night. We can photograph it
happening.
Or view in youtube.
The stars seem to trail out into long curved lines. Can you see
which the pole star is? This the one hardly moves at all because it
is right above the North Pole of the earth.