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Eclipse means that the moon revolves around the earth and moves between the sun and the earth. If the sun, the moon and the earth are just in a straight line, the moon blocks the sunlight that hits the earth, and the shadow behind the moon just falls on the earth. At this time, the eclipse happened. People in the shadow of the moon on the earth began to see the sun gradually weakening, and the sun was covered by a circular shadow. When the sky is dark and completely covered, the brightest stars and planets can be seen in the sky. After a few minutes, the sun gradually emerged from the shadow edge of the moon and began to shine and make the last contact. Because the moon is smaller than the earth, only people in the shadow of the moon can see the solar eclipse. Total lunar eclipse occurs when the moon blocks all the sun, partial solar eclipse occurs when the moon blocks part of the sun, and annular solar eclipse occurs when the moon blocks the central part of the sun. The duration of the total solar eclipse shall not exceed 7 minutes 3 1 sec. The longest time of annular eclipse is 12 minutes and 24 seconds. In order to postpone the observation of the total solar eclipse, a French astronomer chased the shadow of the moon by supersonic plane and extended the observation time to 74 minutes. China has the oldest solar eclipse record in the world, and there have been exact solar eclipse records for more than 0/000 years BC. [Edit this paragraph] Scientifically explain that the solar eclipse is a typical example of the straight-line propagation of light in celestial bodies. When the moon moves between the sun and the earth, it is not always like this. When a lunar eclipse occurs, two conditions need to be met. First of all, the solar eclipse always happens on the first day of the lunar calendar. Not all eclipses will happen on the first day of the lunar calendar, because the orbit of the moon (ecliptic) and the orbit of the sun (ecliptic) are not on the same plane. There is an included angle of 59 between the ecliptic plane and the ecliptic plane. If the sun and the moon run around the intersection of the ecliptic and the ecliptic on the first day, and the sun and the intersection form a certain angle (eclipse limit), an eclipse can occur, which is the second condition to be met. Because the orbits of the moon and the earth are not perfect circles, and the distance between the sun and the moon is near or far, the shadow formed by the sun being blocked by the moon can be divided into umbra, pseudo-umbra (formed when the moon is far away from the earth) and penumbra on the earth. The observer can see the total solar eclipse in the umbra; Annular eclipse can be seen in the range of pseudoumbra; Only a partial solar eclipse can be seen in the penumbra. When the total solar eclipse occurs, it can be divided into five eclipse images according to the positional relationship between the round surface of the moon and the round surface of the sun: 1. Initial loss. The moon moves faster than the apparent speed of the sun. The moon caught up with the sun during the eclipse. When the eastern edge of the moon just "touches" the western edge of the sun, it is called the first loss, which is the first "circumscribed" and the beginning of the solar eclipse. 2. Eat well. About an hour after the initial loss, the moment when the eastern edge of the moon "cuts in" with the eastern edge of the sun is called an eclipse, which is the beginning of the total solar eclipse, when the moon covers the whole sun; 3. Eat a lot. It is the deepest eclipse moment of the sun, and the center of the moon moves to the center closest to the sun; 4.light. The moment when the western edge of the moon and the western edge of the sun "cut in" is called light, which is the end of the total solar eclipse; It usually takes only two or three minutes from eating to lighting, and the longest is no more than seven and a half minutes; 5. Last contact. About an hour after the birth of light, when the western edge of the moon "touches" the eastern edge of the sun, it is called the last contact. Since then, the moon has completely "left" the sun, and the eclipse is over. There are many mountains on the surface of the moon, and the edge of the moon is untidy. At the moment of the lunar eclipse or the arrival of light, when the valley on the edge of the moon can't completely cover the sun, the uncovered part forms a luminous area, like a crystal diamond; The reddish aperture around constitutes the "ring" of the diamond ring, which looks like a diamond ring inlaid with bright gems. Sometimes, many exceptionally bright lights or dots are formed, and it seems that a string of pearls is embedded around the sun, which is called Belle Pearl (Belle is a French astronomer). Whether it is a partial solar eclipse, a total solar eclipse or an annular solar eclipse, the time is very short. The area where the solar eclipse can be seen on the earth is also limited, because the moon is relatively small and its umbra is relatively small and short, so the umbra will not sweep the earth for a long time. Because the average length of the umbra of the moon (373,293 kilometers) is shorter than the average distance between the moon and the earth (384,400 kilometers), there are more annular eclipses on the whole earth than total solar eclipses. [Edit this paragraph] The picture shows the reason why part of the sun disappeared. This is the part of the sun hidden behind the moon. This is the first partial solar eclipse in 2005 and the last total solar eclipse observed before March 2006. During a solar eclipse, the sun, the moon and the earth are in a straight line. This total solar eclipse first appeared in the South Pacific, and the area where partial solar eclipse can be observed spanned South America and North America in the south. The scene in the above picture was taken by a hand-held digital camera last Friday. After a day's rain in Mount Holly, North Carolina, USA, some eaten suns temporarily penetrated the dark clouds. After taking a series of images, this best photo of the solar eclipse was combined with another photo that was not very good but had a plane. [Edit this paragraph] The following are the times of solar eclipses around the world in the 20th century (1901-kloc-0/999): 78 days of partial eclipse, 73 days of total eclipse, 7 1 total eclipse and 6 times of total eclipse. 228 [Edit this paragraph] The knowledge of watching solar eclipses is the most popular at present. 0.0 12mm thickness Visual inspection: 5.0 dimming 10000 times Photography: During the period of 3.8, the sun will not emit any extraordinary rays. Observations of solar eclipses are often misinterpreted. The sun will not predict the occurrence of solar eclipse on the earth, nor will it emit other rays, so it is harmless to stay outdoors during the solar eclipse. But when watching the partial eclipse, should we stare or take a look? Although the sunlight during the eclipse is much weaker than usual, if you look straight, it will still hurt your eyes and possibly your cornea. People will stare at or squint at the sun out of curiosity. Of course, the partial solar eclipse is still very dazzling. If you watch the sun for a long time, your cornea will be damaged unconsciously. During the eclipse, the eyes were damaged not because of the abnormality of the sun, but because people were curious and didn't pay attention to the protection methods. No matter whether the eclipse occurs or not, don't look directly at the sun with your eyes; Don't use so-called "sunglasses"; Don't use "sunglasses", not even a few folded ones; Don't look at the image of the sun in the mirror or on the water; Looking at the sun with a welding mirror14; Watch it with a special coated Myra mirror, which can be obtained from the famous planetarium or science museum; Build an aperture projector. [Edit this paragraph] The story of the solar eclipse For the ancient people, the solar eclipse was very terrible. If you can understand the influence of the sun on grain planting and daily life, you will be concerned about why the sun suddenly disappeared in the sky. In ancient China, people thought that the solar eclipse was caused by a dragon devouring the sun, and other civilizations also thought it was an ominous sign. There are many "solutions": playing drums, shooting arrows at the sky, taking objects or people to pay homage, and so on. It is said that there was a fatal solar eclipse report error. This means that two astronomers in China in the 2nd century BC did not report the solar eclipse for some reason. At that time, Emperor China thought he was the son of heaven and attached great importance to astronomical phenomena. He thought it was a hint from heaven, so he invited a group of astronomers to observe the astronomical phenomena regularly. At that time, comets and meteors could not be predicted, but eclipses could be predicted. The two astronomers didn't tell the emperor about the solar eclipse, and the emperor was furious and beheaded them. Astronomers then were much more dangerous than they are now. [Edit this paragraph] The knowledge about solar prominence is a phenomenon of solar activity that protrudes beyond the edge of the sun's surface. When a prominence appears, the color ball in the atmosphere resembles a burning grassland, and the rose-red tongue-shaped gas rises like a fire, with different shapes, some like clouds, some like arch bridges, some like fountains, some like clumps of grass, and some are as beautiful as festive fireworks. On the whole, they are shaped like earrings attached to the edge of the sun, hence the name "prominence". Prominences rise about tens of thousands of kilometers. Large prominences can be hundreds of thousands of kilometers higher than the surface of the sun, with a general length of about 200,000 kilometers, and individual prominences can reach 1.5 million kilometers. Prominences are much darker than the photosphere, so they can't be observed with the naked eye at ordinary times, and can only be seen directly during a total solar eclipse. Prominence is a very strange phenomenon of solar activity. Its temperature ranges from 5,000 to 8,000, and most prominence materials rise to a certain height, and then slowly land on the surface of the sun. However, some prominences float in the lower corona, and the temperature is as high as 2 million K, which is just as strange as a piece of unmelted ice in a hot steelmaking furnace. In addition, the density of prominence material is 654,330 higher than that of corona material. Corona The outermost atmosphere of the sun is called the corona. The corona extends several times to dozens of times the diameter of the sun. In the most active year of solar activity, the corona is close to a circle; In quiet years, it is oval. B] There are large irregular dark areas in the corona, which are called coronal holes. Coronal hole is an area with low gas density in the corona. There are three kinds of coronal holes: polar coronal holes, isolated coronal holes and extended coronal holes. The sun will lose matter in the form of solar wind-particle flow. Coronal hole is an important source of high-speed solar wind. Coronal Mass Ejection (CME) is a very macroscopic distribution of matter and magnetic field in the corona, and it is a sudden explosion of large-scale dense plasma. Nothing can affect the earth more than it. When there is a strong explosion and coronal mass ejection on the sun, the powerful plasma flow carried by the solar wind can reach the polar regions of the earth. At this time, the aurora appears at the poles of the earth. The forms of aurora are ever-changing. Aurora has also been found on some planets with magnetic fields in the solar system. Flares occurring in the corona are called X-ray flares, and their wavelength is only 1 ~ 8 Angstroms or less. It directly causes the disturbance of the earth's ionosphere, thus affecting the earth's short-wave communication. A jet phenomenon of solar photospheric matter in solar waves. It usually occurs over sunspots and has strong reproducibility. When a broken wave falls behind along the rising path, it will trigger a new broken wave to take off, and so on, but the scale and height are getting smaller and smaller every time until it disappears. Surfing on the edge of the sun presents a small and bright hill with a sharp spike at the top, which grows rapidly. The height of the rise is different. Small surfing is only a few hundred kilometers, big surfing can reach 5000 kilometers, and the maximum surfing can reach 1 ~ 20000 kilometers. The maximum speed of the projectile can reach 100 ~ 200 kilometers per second, which is more than 100 times faster than the fastest reconnaissance plane. When they reach the highest point, they begin to descend under the influence of the sun's gravity until they return to the surface of the sun. From the high-resolution observation data, it is found that surfing is composed of a very small bundle of fibers, and the distance between each fiber is very small. They shine together and move together as a whole. It is more and more important for modern life and production to predict the changes of the state of the sun and the earth's space environment through solar activities. As mentioned earlier, X-ray flares directly cause ionospheric disturbances on the earth, thus affecting short-wave communication on the earth. Solar proton events will endanger the sensors and control equipment of astronauts and spacecraft, and also pose a radiation threat to passengers and crew flying at high latitudes. According to statistics, strong solar activity is related to earthquakes, volcanic eruptions, droughts and floods, heart and nervous system diseases and traffic accidents. Therefore, solar activity and solar-terrestrial physical prediction are very important. Solar activity forecast is divided into long-term, medium-term and short-term forecasts and warnings. As a systematic scientific research object, the space environment of the sun and the earth began in 1957 when humans entered space. The 1950s and 1970s were the exploration stages, and people gradually realized the importance of space environment. On the basis of a lot of exploration, a static model describing the environment is established, and some important space activities are predicted for safety. After the 1980s, driven by the demand for help, the research on space environment between the sun and the earth has developed rapidly. Since 1979, the international conference on solar-terrestrial prediction has been held every four years as scheduled, and its scale is also expanding. In order to unite and coordinate the work of major countries, a joint early warning center was established. Headquartered in the United States, there are 10 regional alarm centers distributed all over the world. Our Beijing alarm center is one of them. After entering the 1990s, scientists vividly called it "space weather". The average solar cycle is 22 years, including two sunspot cycles of 1 1 year. In each cycle, the polarity of sunspots is opposite, and the changes of other solar phenomena have two highs and two lows like sunspots. These solar phenomena include prominence, flare and frequency fluctuation of magnetic effect, and magnetic effect includes aurora and enhancement of radio interference to the earth. The basic cycle of sunspot 1 1 year (sometimes called solar cycle) was discovered by Schwabe in 1843. Some people try to link the solar activity cycle with the changes of other phenomena, such as small changes in the diameter of the sun. Even the change of tree rings is related to the solar cycle. A sunspot is a sunspot. On the photosphere of the sun, there are some swirling airflow, such as a shallow disk, which is concave in the middle and looks black. These rotating air currents are sunspots. Sunspots themselves are not black. The reason why it looks black is that its temperature is one or two thousand degrees lower than that of the photosphere. Against the brighter photosphere, it becomes a black spot with no light. Sunspot is a kind of solar activity on the photosphere, and it is the most basic and obvious phenomenon in solar activity. It is generally believed that sunspots are actually a huge vortex of hot gas on the surface of the sun, with a temperature of about 4500 degrees Celsius. It looks like some black spots because it is lower than the surface temperature of the photosphere of the sun. Sunspots rarely move alone. Often appear in groups [edit this paragraph] The earliest solar eclipse record is BC1265438+May 26th, 2007. People living in Anyang, China are engaged in all kinds of normal activities, but an amazing thing has happened. People looked up at the sky, and the radiant sun suddenly appeared a gap, and the light was dim. However, after missing a large part, it began to recover. This is the earliest solar eclipse record in human history. It was carved on a piece of Oracle Bone Inscriptions. The observation of solar eclipse in ancient China kept the continuity of records. For example, Spring and Autumn Annals records that there were 37 eclipses in 244 years from 770 BC to 476 BC. The record of solar eclipse from the 3rd century A.D. continued to modern times, lasting 16700 years. [Edit this paragraph] The longest solar eclipse (the moon is between the sun and the earth) lasts for 7 minutes, 3 1 second. 1955 occurred in western Philadelphia, and the solar eclipse lasting 7 minutes and 8 seconds was the longest in recent years. It is predicted that there will be a solar eclipse lasting 7 minutes and 29 seconds in the middle of the Atlantic Ocean in 2 186. 1995, a mother and son were photographed during an eclipse in Bangkok, Thailand, which was a total solar eclipse in some parts of the country. The longest duration of an eclipse (the shadow of the moon moving to the earth) is 1 hour and 47 minutes. On July 16, 2000, people saw this scene on the west coast of North America. Because the orbits of the moon and the earth are not perfect circles, and the distance between the sun and the moon is near or far, the shadow formed by the sun being blocked by the moon can be divided into umbra, pseudo-umbra (formed when the moon is far away from the earth) and penumbra on the earth. The observer can see the total solar eclipse in the umbra; Annular eclipse can be seen in the range of pseudoumbra; Only a partial solar eclipse can be seen in the penumbra. [Edit this paragraph] The best observation points for the year, month, day and type of the ten-year solar eclipse schedule are in Antarctica and around the Pacific Ocean on August 20081Canada, the Arctic Ocean, Russia and China on October 26, 2009, ring the atlantic, the Indian Ocean, Indonesia on July 22, 2009, India, China and the Pacific Ocean on October 2010. Africa periphery, Indian Ocean, Myanmar, China 2065438 Pacific Ocean 20 13 5 10 Australia periphery, Irian Island, Pacific Ocean 2013 all ring the atlantic, Africa 20 14 4 29 circumpolar South Pole 20/kloc. Arctic Ocean 20 16 3 9 All Indonesia, Pacific Ocean 20 16 9 655 South America 20 19 12 26 Arabian Peninsula, India, Indonesia, Pacific Ocean 2020 6 2 1 neighboring Africa, Arabian Peninsula, Pakistan, China, Pacific Ocean 226. 2 15 Pacific Ocean, southern South America, Atlantic Ocean 202 1 6 10, northeastern North America, Arctic Ocean, Russian 202 1 65438 Atlantic Ocean 2024 10 3 Pacific Rim, southernmost South America and Atlantic Ocean 20262/kloc. Indian Ocean 2026 8 13 All Arctic Ocean, Greenland, Atlantic Ocean, westernmost point of Europe 2027 2 6 Pacific Rim, southernmost point of South America, Atlantic Ocean 2027 8 2 Atlantic Ocean, Far North Africa, Far South Asia, Indian Ocean 2028 1 26 Pacific Rim, North Tucao China's solar eclipse this year. On August 1 day, a great event happened in our country. The occurrence of total solar eclipse mainly includes several time nodes: the first loss, the moon approaching the sun, the moment when the moon's apparent circle is tangent to the sun's apparent circle for the first time, and the solar eclipse begins; A solar eclipse is the closest moment between the center of the moon and the center of the sun. At this time, the part of the sun that is covered is the biggest. During the total solar eclipse, the solar eclipse is when the sun is completely covered; The last contact, the moment when the moon's apparent circle surface is tangent to the sun's apparent circle surface for the second time, that is, the end of the eclipse is seen here. The following is the timetable of total solar eclipse in major cities of China, in which the time is Beijing time, and "-"means that the city can't see the specific time when the total solar eclipse occurs. The public who can't see food will see a beautiful sunset with food, while the public who can see food is relatively lucky. They can see that the sun is completely covered by the moon. Of course, the luckiest people can see the public in the last contact, because they can see the whole process of the total solar eclipse. The first place name is lack of food, which is very round. Beijing18:17:19:10: 02—Tianjin18:19: 08. 0 minutes 2 1 sec 19 hours 13 minutes 27 seconds-Taiyuan 18 hours 20 minutes 49 seconds 19 hours 14 minutes 26 seconds-Hohhot 18 hours/. Yang 1 8:13:12:19: 04: 24-Changchun18: 09: 42:19: 00: 36-Harbin 8: 287 seconds ——————————— Nanchang18: 33: 48 ————————————— Jinan18: 22: 02: 09:14:/. Wuhan18: 31:30 —————————— Changsha 18: 35: 19: Guangzhou18: 42: 36 ————————— 32 minutes and 57 seconds 19:27:34- Guiyang 18: 39, 19: 32, 0 1- Kunming 18: 42,18:. 19: 31:42: 20: 24: 44 Xi 'an18: 26: 4619: 20: 50 —— Lanzhou18: 24: 0/. 438+09:19: 24: 20:12: 00 Yinchuan18: 20: 03:19:15: 31-Urumqi 1 1 sec-Mohe 17: 55, 10: 08: 47, 33: 19: 37: 33.