In fact, generally speaking, we observe the apparent motion of the sun and the moon on the imaginary celestial sphere from the earth. Because the apparent motion of the moon from west to east is faster than that of the sun, the solar eclipse always starts from the western edge of the sun to the east. Because the speed of the moon shadow sweeping from west to east on the earth (about 1km/s) is faster than the rotation speed of the earth's surface (less than 0.5km/s on the equator), the moon shadow moves from west to east on the ground, so the time to see the solar eclipse in different places on the ground is different, and the solar eclipse is seen in the west before the east. Due to the small cross section of the umbra cone on the ground, the width of the total lunar eclipse zone is only two or three hundred kilometers. As far as a place is concerned, the duration of the total solar eclipse-"lunar eclipse" is very short, the longest is only more than 7 minutes, and the shortest is only 20 seconds. In order to prolong the observation time of the total solar eclipse as much as possible, people follow the flying moon shadow by plane. For example, on June 30th, 1973,/kloc-0, French scientists made an unprecedented 74-minute total solar eclipse observation with Concorde. Only a partial solar eclipse can be seen in the area swept by the penumbra of the moon. Obviously, the observation time of partial solar eclipse is much longer. As far as one place is concerned, the process of three solar eclipses is summarized as follows.

(1) The whole process of total solar eclipse can be divided into five stages:

(1) initial loss. The first contact between the eastern edge of the moon and the western edge of sun gear is called the first loss. The eclipse begins, and then the eaten part gradually increases.

2 eat. The second contact between the eastern edge of the moon and the eastern edge of sun gear is called a lunar eclipse, and the total solar eclipse begins.

Eat a lot. When the center of the moon is closest to the center of sun gear, it is called an eclipse.

(4) light. The third contact between the western edge of the moon and the western edge of sun gear is called photogenesis. The total solar eclipse ended, and then the eaten part gradually decreased.

⑤ Last contact. The fourth contact between the western edge of the moon and the eastern edge of sun gear is called the last contact, and the eclipse is all over.

The landscape of the total solar eclipse is very spectacular. From the first loss, sun gear gradually turned into a crescent moon, and the sky darkened, as if night fell and birds returned to their nests. From the beginning of the eclipse, darkness suddenly descended, and a reddish aperture appeared around sun gear, which was covered by the moon. This is the chromosphere of the sun's atmosphere, and several flare-like prominences often appeared. If you look closely, sun gear appears silvery gray, which is the sun's outer atmosphere-corona. Near the light, the edge of sun gear suddenly shines like jewels, which is amazing, because the bright sun gear shines through the exit of the moon wheel edge. Total solar eclipse is not only short-lived, but also rare. A typical total solar eclipse has a bandwidth of about 160 km and a length of about 9700 km, so the total solar eclipse area is only1550,000 square kilometers, which is only 1/305 (about 5 1 100 million square kilometers) of the total surface area of the earth. As far as the whole earth is concerned, there is a total solar eclipse every 1.5 years on average, so people who don't leave their places will have a chance to see a total solar eclipse every 450 years, that is to say, many people may not even see it for a lifetime. I'll believe that when I see it. In order to witness the spectacle of the total solar eclipse, people had to travel all the way to the place where the total solar eclipse occurred.

(2) The whole process of annular eclipse can also be divided into five stages:

(1) initial loss. The tangent between the eastern edge of the moon and the western edge of sun gear is called the first loss. The eclipse begins, and then the eaten part gradually increases.

② The eclipse begins. The interconnection between the western edge of the moon and the western edge of sun gear is called the beginning of the annular eclipse.

Eat a lot. The nearest distance between the center of the moon and the center of sun gear is called an eclipse.

(4) The end of the eclipse. The inscribed line between the eastern edge of the moon and the eastern edge of sun gear is called the end of the annular eclipse, and the portion eaten gradually decreases after the annular eclipse.

⑤ Last contact. The western edge of the moon and the eastern edge of sun gear are circumscribed for the last contact, and the eclipse process is all over.

(3) The whole process of partial solar eclipse can be divided into three stages:

(1) initial loss. The eastern edge of the moon and the western edge of sun gear were cut off as the first loss, and they began to be partial eclipse, and then the eaten part gradually increased.

Eat a lot. When the center of the moon is closest to the center of sun gear, it is called an eclipse.

③ Last contact. The western edge of the moon and the eastern edge of sun gear are circumscribed for the last contact, and the eclipse process is all over.

The degree of solar eclipse is expressed by "food score", which is defined as the ratio of the covered part of sun gear to the diameter of sun gear when the food is heavy. Total solar eclipse is slightly larger than 1, annular solar eclipse is slightly smaller than 1, and partial solar eclipse is smaller than 1.