Higher tier: Galaxies
Galaxies are huge collections of stars like our Sun.
Our Sun belongs to a spiral galaxy called the Milky Way.
Astronomers estimate that the Milky Way is a collection of about 100 thousand million stars.
That’s 100,000,000,000 stars.
Our solar system lies in one of the Milky Way’s four spiral arms, nearly two thirds of the way from the centre.
Part of the Milky Way is visible on a clear night from Earth, as a thick band of stars stretching across the sky.
The Milky Way galaxy is home to planet Earth
