THE SUN

BY LIAM CUMMINGS

• The sun is the solar system’s power source

• It provides light on earth to have life, night and day and plants.

THE SUN

INFO

• The sun is a big gas ball made out of helium, which is formed when hydrogen atoms fuse together.

• The Greek’s named it Helios, from which we retain the adjective heliocentric of the sun.

What will become of it?

Like everything else, the sun will not last forever. But the time it has left may seem forever with you.

The sun has about 4-5 billion years left and when it runs out the results are devastating.

The Sun's core will collapse under its own gravity. At the same time, its atmosphere will become unstable and start to expand, transforming the Sun into a huge red giant star.

How will this affect Earth?. Although it will fare better than closer planets like Mercury, which will be completely engulfed by the swelling Sun, Earth will be entirely vaporised and all life on our planet will end.

What Else?There’s more. Over the following billion years the Sun will gradually die. As a star's core crashes inwards, it eventually becomes hot enough to ignite another of its constituent atoms, helium. Helium atoms fuse together to form carbon. Helium burns faster than hydrogen, so this stage is much shorter and only lasts a few million years.

What happens when Helium runs out?

When the helium supply runs out, the centre again collapses and the atmosphere again inflates. The Sun isn't massive enough to fully re-ignite its core for a third time and so goes on expanding, shedding its atmosphere in a series of bursts. The dying core eventually forms a white dwarf - a spherical diamond the size of the Earth, made of carbon and oxygen. From this point on the Sun will gradually fade away, becoming dimmer and dimmer until its light is finally snuffed out.

In 4 billion years time, this thing won’t exist any more

Facts

In the middle ages the Sun was thought to have orbited the Earth. It wasn’t until Nicolaus Copernicus in the 16th century came up with the idea of the Earth actually orbited the Sun. He was absolutely right, but people ignored him, until Isaac Newton came up with the formula for his laws of motion, successfully modelling the dynamics of the solar system.

More Facts

• The temperature of the sun can reach astonishing temperatures of 5500 degrees centigrade on it’s surface and a sweltering 15.6 million degrees centigrade in it’s core!

To find out more go to: www.bbc.co.uk/planets