Milky Way

Part of the Milky Way

Milky Way

Our galaxy is thought to be at least 100,000 light years across and have more than 100 billion stars.

The Milky Way is a spiral galaxy with a bulge at its centre and a surrounding spiral disc of stars, gas and dust.

The entire galaxy rotates around a central axis. Since the dinosaurs died out about 65 million years ago, the Sun is estimated to have travelled about a third the way around the Milky Way's centre.

Image: A Spitzer Space Telescope infrared image of hundreds of thousands of stars in the Milky Way's core (credit: NASA/JPL-Caltech)

Watch and listen to clips from past programmes TV clips [9]

Part of the Milky Way

Introduction

The Sun is one of countless stars in our galaxy.