Solar and lunar eclipses are quite unusual astronomical phenomena which can usually be observed not more often than two-three times a year. In the ancient time people were afraid of eclipses and considered them harbingers of troubles in spite of the fact that the reasons of eclipses were quite clear described still by Thales Miletsky living in Ancient Greece.
Instruction
1. The first documentary mention of a solar eclipse occurred on October 22, 2137 BC in Ancient China when the emperor Chung-Kang ruled Celestial Empire. In those far times thought that the monster is going to absorb a star, and drove away it in the various ways – shouts, a rappberry and throwing of copies towards the sun. They always managed it, the full phase of a solar eclipse cannot longer last eight minutes.
2. The solar eclipse is a shadow of the Moon which mono to see when solar and lunar orbits are crossed, and the Moon blocks itself a star. Considering various distance of these objects from the globe, visually solar and lunar disks coincide by the size, and visibility of the fact that the sun disappears is created. Not everyone can see it a minute of a total eclipse, and only those who got to a zone of a shadow, which diameter about two hundred kilometers. In a radius about two thousand kilometers it is possible to see only a partial solar eclipse, and those who are too far from a zone of a lunar shadow, at all nothing will be noticed.
3. It is necessary to observe a solar eclipse very carefully, it is dangerous to eyes. Despite the numerous light filters existing today, the best way to protect eyes are still a zakopchenny glass and the lit film.
4. If solar eclipses are possible only in a new moon, then lunar - on the contrary, occur only in a full moon. The lunar eclipse happens at the moment when to the Moon the shadow which is cast by Earth falls. If the Moon appears completely in a zone of this shadow, the total lunar eclipse is visible if is not present – that private. Lunar eclipses, unlike solar, look equally in every spot on the globe if only in the sky in general it is possible to make out the moon, and they are much more long: the maximum time of a full phase of a lunar eclipse is hundred eight minutes.
5. In spite of the fact that lunar and solar eclipses caused in people horror throughout the millennia, learned to predict them in ancient Babylon, having noticed that all eclipses repeat from one period to another. This period carries the name "saros" today and 18 years 11 days and 8 hours last. During this time there are 28 lunar eclipses, about forty solar, and by means of a saros it is possible to predict these unusual astronomical phenomena for the whole three hundred years ahead.