Under The Martinborough Stars

The Sun, NASA images.

Another glorious summer is here! I’m saying this while sitting my cold office listening to the rain pound on the roof. We expect summer to be, well sunny don’t we?

Stars create heat and light by combining simple elements in their core. All the stars we see in the sky do just this. Our sun is a star, but it is the only Sun. We can also call the Sun Sol, hence the name of objects that use the Sun, like Solar panels, Solar glasses, Solar System etc. 

Our yellow Sun is pretty much an average star, not too big or too small, too old or too young, or too big or too small- very average actually. It is approximately 150 million km from the Earth and is so massive that it holds 99% of all the mass in the Solar System. You could fit 1 million Earths inside the Sun.

Our Sun is busy changing hydrogen into helium and a little sprinkling of carbon, nitrogen and oxygen to boot. It does this via nuclear fusion, very simply, by ripping atoms of hydrogen apart and then squishing them back together to form a new element helium. It has been doing this for 4.5 billion years and is expected to keep going for another 4.5 billion years. 

With all this nuclear fusion going on, the waste product is photons. That is what is making the Sun shine. But the photons don’t get an easy time of it. Leaving the core of the Sun, these packets of energy are bounced around, ricocheting off atoms inside the sun, until eventually they reach the surface. For one photon of light to reach the surface takes 200,000 years! 

The light from the Sun, takes a much quicker time to reach us, only 8 and a half minutes. The Sun is really quite close, with light taking 8 and half minutes to reach us. It still means that when you see the Sun, you are technically seeing it in the past, 8 and half minutes ago. If, it was to disappear, you wouldn’t know for 8 and a half minutes.

What will happen to the Sun in another 4.5 billion years? Will it explode? Well, no actually. It is the wrong colour- namely yellow. Only the biggest hottest stars will supernova or go bang, ours will slowly get a bit bloated, swallow up Mercury and Venus and probably Earth then lose its grasp off its outer layers. What will remain is the core of the star, which we call a white dwarf.

This summer, take more notice of the Sun when it does appear and think about just how big and old it is. Then go out and enjoy it.

Becky Bateman, owner of Under The Stars NZ, a stargazing business here in the Wairarapa