Every two years or so, there is a total solar eclipse somewhere on the Earth, in Africa, in Asia, in America and sometimes in Europe as it was on August 11, 1999.
How does an eclipse occur? A long time ago, it was thought that a dragon was “eating” the Sun and it was thought that by scare it and shouting that dragon would retreat and make the Sun. And in fact, after a few minutes the Sun came back … Today obviously we know that all this is false and is part of the folklore.
In reality it is the Moon that comes to interpose just in the axis between the Sun and the Earth. By a happy chance its diameter exactly hides that of the Sun. When the three bodies are perfectly aligned, for a few minutes we can observe the crown that surrounds the Sun. It is a very large region that represents the outer atmosphere of the Sun whose density is extremely low. It is so weak that the sun’s light prevents us from observing it outside eclipses. Sometimes the Moon only partially hides the Sun’s disk, it is the partial eclipse of the Sun. In this case his disc takes the form of a crescent more or less indented.
But here also you must use one of the three methods described previously (use a Mylar filter for example) to observe the Sun, even when it forms a crescent end. It is only at the time of the “Black Sun”, of the total eclipse where appears the solar corona that you can withdraw your filter and to observe the Sun without precaution. Then do not forget to put it back because the Sun will quickly reappear.
The same eclipses are repeated after several decades. They follow a very long cycle that lasts 18 years and 11 days, called the Saros after which the Sun, the Moon and the Earth find the same relative positions in the sky. But other orbital perturbations modify this rhythm, so that after the solar eclipse of August 11, 1999, there will be no new total eclipse in Europe before 2026, and again, it will occur in the north of Spain.
Total eclipses are extraordinary phenomena. Do not hesitate to take a trip and take the opportunity to observe this phenomenon. You will remember all your life so the atmosphere is exciting and seems supernatural.