Is Our Sun The Only One?

The Sun is a massive hot ball of brightly glowing gas. Deep within the Sun, nuclear fusion reactions take place. These reactions produce vast amounts of energy, causing the Sun to emit the whole range of electromagnetic waves. The Sun, however wonderful it is, unique it is not. There are probably billions of other stars. Compared to other stars, the Sun is quite small and not very bright. But it is our closest star, so other stars look tiny in comparison because they are so much further away.

Each galaxy contains a vast number of stars all held together by gravitational forces. The Sun is just one of around 100 000 million stars in the Milky Way galaxy. The Milky Way is not the only galaxy in the Universe. Large telescopes can detect millions of galaxies can be seen in all directions in space. The Universe is made up of billions (thousands of millions) of galaxies.