For life on Earth, the Sun is the most important thing there is. It produces almost all the energy we have-even the energy inside coal and oil originally came from the Sun. Because the Sun is the largest body in the solar system, all the planets and other bodies are held in orbit around it by the pull of the Sun’s gravity.
The Sun is Earth’s nearest star. If you were to travel far into space, the Sun would look just like the other stars. And, like the stars, it is a huge globe of hydrogen and helium gas which produces enormous amounts of heat and light. How do the Sun and stars do this?
 Because the sun is so bright, you should never look straight at it. Its light can seriously damage your eyes and even blind you. Astronomers use special methods to study the
Sun safely.
 Special equipment shows different types of radiation coming from above the Sun’s surface. Sunspots can be clearly seen in the red light of hydrogen from just above the surface. Higher up, ultraviolet light shows prominences, while X-rays show activity in the
Sun’s outer atmosphere.

A total solar eclipse happens when the Moon is directly in front of the Sun. For a few minutes, the Moon covers the Sun, and we can see the Sun’s outer atmosphere, called the corona, around the disk of the Moon.


Sunspots look dark because they are four times fainter than the rest of the Sun.
If you could see them by themselves, they would be brilliant. The layers of the
Sun’s atmosphere- the chromosphere and the corona- get hotter as go outward.
Nuclear energy
The hydrogen in the Sun and stars is not burning, but produces nuclear energy. The temperature has to be very high for nuclear energy. The temperature has to be very high for nuclear energy to be made around 27 million °F, which is the temperature at the center of the Sun. At this heat, the particles of the hydrogen gas jostle together. If the particles hit one another, they can be forced to join up, forming helium out of hydrogen, and giving off energy at the same time. The energy makes its way out from the center and eventually escapes from the surface as light and heat. This is the same thing that happens inside a hydrogen bomb.
The Sun changes 600 million tons of hydrogen into helium every second. As it does this, it loses four million tons of its mass, which escapes as light and heat energy. The Sun has been doing this for five billion years, but there is enough hydrogen left in the Sun for it to keep producing energy for another five billion years.
The shining surface of the Sun is called the photosphere. It is not all brilliant light, however-there are darker markings on it, called sunspots. These are the areas where the Sun’s magnetic field reaches the surface and cools it down slightly, making it less

bright. Many sunspots are much bigger than Earth, but they usually last only a week or two.
The magnetic field also gives rise to clouds of glowing gas above the photosphere, called prominences. These are faint compared with the photosphere, but astronomers using special equipment can see them around the edge of the Sun. Solar flares are brighter than prominences, and are great releases of energy that throw out huge streams of particles from the Sun. the largest flares can even affect communications on Earth.