The Earth tries to pull everything down towards its centre.
This pull is called the force of gravity (the invisible force).
When you lift things up you have to pull against gravity.
If you drop a pencil, gravity pulls it to Earth.
If you rest its mid-point on your finger, gravity will pull down equally on both sides of the pencil and it will balance in the air.
Did you know that there is no gravity in space? This is why astronauts float around in their spaceships.
Did you know that there is gravity on the Moon?
The gravity on the Moon is much weaker than the gravity that we have here on Earth.
This is why moon walking for astromauts is very difficult.
The
Earth tries to pull everything down
towards its centre.
