Learn About Different Models of the Solar System

Can you remember how many planets are in our Solar System?

This diagram shows us all eight planets orbiting the Sun, which is a star at the centre of the Solar System.

Models of the Solar System

This model of the solar system is called a heliocentric model.

Heliocentric means the Sun is at the centre (the Sun is in the middle of the Solar System).

Until the 1500s, people thought the Earth was at the centre of everything we could see in the sky. This was a geocentric model (meaning Earth is in the middle).

When astronomers (people who look up at the sky, stars and planets) used to look up at the sky, they thought everything in the sky was moving around our planet Earth.

When you look at the sky, it does look like the Sun and moon move around us, so when other astronomers began to disagree with the geocentric model, lots of people did not believe them.

Thanks to an astronomer called Nicolaus Copernicus, we now know that the Earth rotates on its own axis and orbits the Sun.

Galileo agreed with Copernicus and used a telescope to prove it.

In this activity, you’ll be answering questions about the geocentric and heliocentric models of the Solar System. 

Don't worry if that sounds a bit daunting - you can look back at this page at any point by clicking on the red help button on the screen.