It would seem, such interesting event as a solar eclipse, there has to be each new moon when the satellite of Earth passes over it, closing a disk of the Sun. But for some reason of an eclipse occur less often.
Instruction
1. The solar eclipse is a shadow from the Moon on the Earth's surface. Diameter of this shadow is about 200 km, it is much less, than diameter of Earth, and the Moon is less than Earth. For this reason the eclipse of the Sun is observed only in rather narrow strip of a lunar shadow. Observers who are in a shadow strip see a total eclipse of the Moon, at the same time the Moon closes the Sun completely. The firmament darkens, in it stars become visible, becomes more cool. Outdoors it is possible to notice how the birds puzzled with sudden darkness sharply become silent, they try to take refuge in nests. Flowers are closed, animals quite often show concern. The total eclipse of the Sun does not last long.
2. People who are in close proximity to a lunar shadow or on its border observe a partial eclipse of the Sun. The moon passes on the Solar disk, closing it not completely, and only touching on edge. The sky darkens much less, stars are not visible, the effect reminds rather storm cloud which floated on the sky - therefore the partial solar eclipse can and be not noticed. It is observed approximately in 2 t of km from a zone of a total eclipse. There is a solar eclipse always in a new moon when the Moon is not visible from Earth as it is not lit with the Sun. Therefore it seems that in the Sun the huge black spot which undertook is unknown from where. The shadow cast by the Moon to Earth has the form of a cone which edge is further the planet. Therefore the shadow from the Moon represents not a point, but rather small spot moving with a speed of 1 km/s on the surface of the planet.
3. Therefore the maximum duration of a full phase of an eclipse - 7.5 minutes. The private eclipse can continue about two hours. The solar eclipse is the unique phenomenon and it is possible only because because of the difference of distances in the heavenly sphere diameters of the Moon and the Sun practically coincide if to look at them from the Earth's surface. The Sun is farther from Earth, than Long, by 400 times, and diameter exceeds it lunar approximately by 400 times. An orbit of the Moon which rotates around Earth not round, but elliptic and therefore during the moments, favorable for eclipses, the lunar disk can be more solar, it is equal to it or to be less. If the disk of the Moon is equal to a disk of the Sun, the total eclipse steps only on a second and if it is less - that eclipse is called ring-shaped as around a dark disk of the Moon the bright ring of the Sun is visible. This longest eclipse, it can continue up to 12 minutes. When there is a solar eclipse, it is possible to observe a crown of the Sun - external layers of the atmosphere of a star. At usual light it is not visible, but at the time of an eclipse it is possible will enjoy this show shaking on the beauty.