Why are the Earth, the Sun and the Moon spheres?
Because gravity pulls everything towards the centre.
What does every object with mass have?
Gravity
If an object has more mass, how is its gravity?
The more mass an object has, the stronger its gravity.
Why is the Moon’s gravity weaker than Earth’s?
Because the Moon is smaller and has less mass.
Why is the Sun’s gravity much stronger than Earth’s?
Because the Sun is much bigger and has more mass.
What does the Earth’s gravity pull towards the centre?
Everything, even itself.
What is the Earth made of that gravity pulls inward?
Rock (and other materials).
What does “spherical” mean?
It means having the same shape as a ball.
What is the Sun made of?
The Sun is made of gas.
What is the Moon made of?
The Moon is made of rock.
What is the Earth made of?
The Earth is made of rock, water, and air.
