The Sun
Without the sun, there would be no life on earth.
Warmth, light, rain and wind are all generated by the sun.
But that‘s not all: The sun‘s rays also provide us with enormous amounts of energy!
Is the sun the size of a watermelon?
No, it‘s much bigger of course. The sun has a diameter of about 864,000 miles. This distance is the same as 109 planet earths strung together like a necklace, or the same as the length of a piece of string wrapped around the earth 35 times. In the hot center of the sun there is enough space for as many as 1,300,000 planet earths. You can see the difference if you put a watermelon next to a pea. If you think of the watermelon as the sun and the pea as the earth it gives you a good idea of just how huge the difference
is.
A fiery oven in outer space.
The sun is a giant ball of white-hot gases. The temperature on the surface of the sun is around 11,000 °F. It‘s so hot that the surface of the sun bubbles like a saucepan full of boiling soup. And the further you go into the sun, the hotter it gets. At the sun‘s core the temperature reaches an incredible 27,000,000 °F. Your oven at home in the kitchen has a maximum temperature
of around 450 °F. This is fine for baking cakes but if you tried to bake a cake in the sun it would be burnt to a crisp instantly.
How heavy is the sun?
The sun is by far the largest object in our solar system. It accounts for almost the entire mass of our solar system; 99,87% to be precise. All the planets together make up the 0.13% that‘s left over. That sounds pretty complicated but it‘s actually quite simple. Imagine that a hundred marbles represent the mass of our solar system (i.e. the sun and all the planets). If you were to take one of those marbles and cut off a little piece, that little piece would be the mass of all the planets.
The remaining pile of 99 marbles plus the one with the bit cut off would be the mass of the sun. The weight of the sun in tons, written as a number, is a 2 with 27 zeros after it. This is what it looks like: 2,000,000,000,000,000,000,000,000,000 tons That is 333,000 times the earth‘s mass!
How long would it take for a human being to get to the sun?
The distance from the earth to the sun is approximately 94 million miles. Sometimes the sun is a little further away, sometimes a little closer, depending on what season it is. That‘s so far that it would take 4,400 years to get there on foot, 166 years by high-speed train and 22 years by jumbo jet. The sun‘s rays, however, travel so fast that it only takes them 8 minutes to get from the sun to the earth. Light travels 186,000 miles per second, which makes it a million times faster than a jet plane.
Has the sun always been there?
The sun was born out of a giant cloud of cool gas and dust around 5 billion years ago. That‘s difficult to imagine when you know what it‘s like today. It‘s no longer cool at all, but has become a giant, ball of white-hot gas, able to give off its own light. The scientific word „stars“ is used for all celestial
bodies which radiate light. The planets of our solar system, including the earth, revolve around the sun. Planets cannot create light themselves so it would be permanently dark and cold on earth if it wasn‘t for the sun. The sun will exist for around another 5 billion years, getting hotter and bigger all the time. It will get so huge that its surface will even touch the earth. Then it will explode and a new solar system might form. But don‘t worry! There‘s an extremely long way to go before that happens. The sun will almost certainly outlast the human race.
Be careful!
When studying the sun you should never look directly at it. Never use binoculars
or a telescope to look at it even if there is a solar eclipse! Looking directly at the sun can seriously damage your eyes and even lead to blindness.
Sunglasses, even very dark ones, do not provide enough protection. You can buy suitable filters and glasses from an optician or at a planetarium.
Why is the sun so hot?
Even if the sun were not as hot as it is, we wouldn’t be able to walk around on it - we would simply disappear into it. This is because it is composed almost entirely of gases and only a very small proportion of metals. Gases are like air and, as you know, we can’t stand on air. If we could, we wouldn’t be able to jump from a diving board into a swimming pool.
The sun consists mainly of two gases: hydrogen and helium. You have probably come across helium at some point, it’s the gas that’s used to fill balloons that rise into the air. The heat in the sun is so intense it turns hydrogen
into helium. So much energy and heat are released in this process that great explosions take place. We can feel the heat from these explosions way out here on earth, but fortunately we are far enough away that we only receive as much heat as we need to live.
Why does the sun rise and set?
We talk about the sun “rising” in the morning and “setting” in the evening. This comes from a time when people still thought the earth was flat and that the sun rose on one side and set on the other. But, as we now know, it isn’t the sun that moves but the earth, even if it doesn’t feel that way to us.
Every day, the earth turns once on its axis. This means that each part of the earth turns to face the sun once (daytime), and once away from the sun (night-time). This process takes exactly 24 hours, which is how the earth’s rotation and sunlight contribute to how we keep track of time. All clocks follow this rhythm exactly.
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