The outer layers of the Sun
The outer layers of the Sun may be observed directly, but ordinarily it is only the thin, visible surface that may be studied in detail from the ground. With the space age quite new possibilities also arrived for studying the Sun in other types of radiation than visible light.
A number of strange and amazing phenomena take place in the outer layer of the Sun. Here we are going to look more closely at these phenomena. |
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| The corona |
| The outer atmosphere of the Sun is called the corona. From the surface of the Earth we may only see this very spacious, hot and strange gas during total solar eclipses. |
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| Why is the solar corona so hot? |
How does the solar corona become so hot, one million °C or more?
It cannot be heated by the radiation from the surface of the Sun where the temperature is “only” 6000 °C. |
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| The solar wind |
| The stream of particles out from the Sun is called the solar wind. Even if the solar wind may seem intense, it is only an insignificant part of the Sun that disappears. |
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| The solar wind and its impact on the tails of comets |
| Comets are huge, dirty snowballs 6-16 kilometres long visiting from time to time the inner parts of the solar system. |
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| The heliosphere and the heliopause |
| Between the stars there is almost empty space, but only almost. |
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| Pioneer 10 heading towards the stars |
| On 28th April 2001 a powerful radio aerial in Madrid was pointed in the direction of the stellar constellation Taurus. An extremely weak, but very important signal was picked up. |
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