Tides
Jake is rudely awoken by the incoming tide
© Richard Duszczak
In astronomy, tides and tidal forces have a lot of other effects.
Tides are caused by the difference in gravity across a planet.
The tides on Earth are mainly caused by the effect of the Moon.
You can see why there are two tides every day with this demonstration.
The tides are also changed a bit by the Sun. When the Sun and Moon are working together, the tides are particularly high, and are known as Spring tides. This happens at the full and new moon.
