A solar eclipse is an astronomical phenomenon in which the Earth, Moon and Sun line up in one line. The diameter of the moon is almost 400 times smaller than that of the sun. But it is located approximately the same times closer to the Earth. Therefore, visually, on the celestial sphere, the diameters of the Moon and the Sun almost coincide. And if the satellite of the Earth partially or completely obscures the star, an eclipse occurs.
The moon's shadow on the Earth's surface is about 200 km in diameter. Therefore, an eclipse is observed only in a narrow strip in the direction of its movement. Since the orbit of the moon is an ellipse, visually its diameter can be greater than, equal to, or less than the sun's. In the first case, an observer in the lunar shadow region sees a total solar eclipse. This is an interesting phenomenon, during which the sky darkens and the stars become visible. There is also a solar corona, which is usually not visible. In the second case, the same thing happens, but only for a moment. In the third, an annular eclipse occurs. A shiny streak of sun is seen around the dark lunar disk. The duration of the phenomenon is up to 12 minutes.
The lunar shadow moves along the surface of the Earth at a speed of 1 km / sec. The maximum possible total eclipse time is 7.5 minutes. But the quotient, in which the disc of the Moon does not pass exactly in the center of the Sun and hides it only partially, can last up to 2 hours.
A solar eclipse is by no means a rare phenomenon. The first in 2012 is expected on May 20. It will be annular. It will start in the south of China, then, from 06.19 to 09.02, it will be observed in Japan. Moreover, in some places, in particular on the island of Hakkaido, from 07.32. local time, a total solar eclipse will be observed for 5 minutes. Further, the lunar shadow will pass through the southern part of Kamchatka and the Pacific Ocean. The eclipse will end in the United States.
It will enter the Pacific coast of Russia on May 21 at 10.31 local time. The maximum phase will be on the Demin Islands. A partial eclipse will be observed in the Far East and Siberia, from Vladivostok to Arkhangelsk. It will last about 3 hours. The southwestern border will run along the Chelyabinsk - Perm - Syktyvkar - Arkhangelsk line. It will end at 13.31 local time in the Bering Strait.
On the territory of China, the eclipse can be observed in the cities of Gangzhou, Henzhen, Fuzhou, Hong Kong, Taipei. In Japan - in Tokyo, Yokohama, Osaka, Nagoya, Kyoto, Shizuoka, Kagoshima. In the USA - in the region of northwestern Texas, in particular in Albuquerque. Extreme observation points - Arctic, Indonesia, Mexico.
