Why is the sun getting hotter

Astronomical knowledge about the sun

Origin and lifespan of the sun

Has the sun always been there?

The sun has been around for around 5 billion years; it emerged from a large cloud of cool gas and dust. You can’t imagine that, because today it’s no longer cool, but a huge, boiling hot gas ball and can light itself up.
Scientists call all celestial bodies that can shine by themselves "Stars". All planets in our solar system revolve around the sun, including our earth. A planet cannot shine by itself, so without the sun it would always be dark and cold on earth. The sun will exist for another 5 billion years and it will get hotter and bigger. It will grow so big that its edge will even touch the earth. It will then explode and perhaps a new solar system will arise.
But don't worry, it will take a long time until then and the sun will definitely be a thousand times older than humanity.

The composition of the sun

Why is the sun so hot?

Even if the sun weren't that hot, we couldn't walk around on it. We'd just fall through it. It consists almost entirely of gases, only a very small part are metals. Gases are like air and we can't stand on air either, otherwise we wouldn't be able to jump off the diving board in the swimming pool. There are above all two gases in the sun, namely Hydrogen and helium. You have surely got to know helium before:
This is namely filled into balloons so that they can rise up. It's so hot in the sun that the hydrogen is fused into helium. This creates so much energy and heat that there are real explosions on the sun. We can still feel the heat of the explosions, but luckily we are so far from the sun that we only get as much heat as we need to live.


day and night

Why does the sun rise and set?

The sun is responsible for our rhythm of life, it determines when we go to sleep and when we get up. In the morning they say:
"None", and in the evening they say:
"The sun sets".
This comes from a time when people still believed that the earth was flat and the sun rose and set from the edge. But in reality the sun does not rise and set at all: in reality the earth moves, even if we do not feel it at all. The earth rotates around itself once a day, around its own axis. As a result, every part of the earth is turned once towards the sun, there is then day, and every part once to the non-illuminated side, there is then night.
It takes exactly 24 hours, so the rotation of the earth and sunlight are also responsible for our time. Every clock follows this rhythm exactly.

The seasons

Why is it warmer in summer than in winter?

The earth does not just rotate on its own axis. It circles the sun once a year on a precisely defined path, which is also the name of this path "Orbit". The orbit is not completely round like a circle, but rather has the shape of an egg. Scientists call this the "ellipse".
The earth rotates around the sun at a speed of approx. 107,000 km / h, which is approx. 2000 times faster than a car is allowed to drive in the city.
Many think that the earth is closer to the sun in summer than in winter and that it is therefore warmer in summer. But that's not true, on the contrary: In summer the earth is even further away from the sun than in winter. But why is it colder in winter than in summer? This is because the earth is a bit inclined in space. That is why the sun's rays never hit the earth straight, but at a certain angle. And depending on what this angle is, we have on earth Spring, summer, autumn and winter and it's warmer or colder.


Source: with the kind permission of SMA Solar Technology AG
The contents of this page may not be transferred to other websites or print products without permission.
You can find printable pdf documents on the subject of "solar is future" in the free area of ​​www.grundschulmaterial.de