English Across the Curriculum
The sun is a star at the centre of our solar system. It is a huge spinning ball of hot gas that lights up the Earth and provides us with heat. Our sun is a medium-sized yellow star that is about 150 million km away from the Earth.
Here are some important facts about our sun:
The sun was formed about 4.5 billion years ago. As a star of the second generation, it doesn't only burn hydrogen but also other elements, like helium and metals. They were formed when a big explosion took place, which formed our solar system.
At the sun's centre, nuclear fusion produces great amounts of energy. This energy turns into heat and light, which warms up the solar system and makes it brighter. The sun has enough energy for about 5 billion years. Then it will explode and a cloud of gas will destroy all the planets of the solar system.
The sun's diameter is about 1.4 million km. It is 10 times larger than the planet Jupiter and over 100 times larger than the Earth. About 1.3 million Earths could fit into the sun. But it is not a big star compared to others in our universe.
The sun - centre of the solar system
Image: NASA, Public domain,
via Wikimedia Commons
The core is the inner part of the sun. It is the place where the star converts hydrogen to helium. The energy travels to the outer parts of the sun as radiation. The photosphere is the surface of the sun. The chromosphere is the lower atmosphere with temperatures of up to 7000° C. The corona is the upper atmosphere. You can only see it during an eclipse. It is one of the hottest parts of the sun with temperatures as high as a million degrees C.
A solar flare happens when the sun's magnetic fields crash into each other. It causes gas to shoot out of the sun. Sometimes these flares shoot up as high as 100,000 km and can last for hours. Solar flares are not really dangerous to us but they can interfere with radio signals on earth.
The eclipse of the sun is one of nature's most spectacular special effects. It happens when the earth passes through the moon's shadow. The moon always has a shadow and if the sun, the earth and the moon are in the right line, the moon's shadow passes over the earth. When this happens the sun is blocked from your view and it gets as dark as night, but only for a few minutes. This shadow might only be a few hundred kilometres wide and people from all over the world come and see it.
The sun gives us heat, light, our food and the air that we breathe. It powers the atmosphere to give us winds and rain. Even coal and oil come from plants and animals that lived millions of years ago and depended on the sun for life. The sun heats the land, the oceans and our air. Green plants use the sun's rays to turn carbon dioxide into the oxygen that we breathe.