the side illuminated by the sun is bright, and the side facing away from the sun is dark. The moon revolves around the revolving earth from west to east, and the relative positions among the sun, the earth and the moon are constantly changing, so that the bright hemisphere of the moon sometimes faces the earth, sometimes sideways, and even back to the earth. In this way, from the earth, the shape of the moon will change regularly.
on the first day of each month in the lunar calendar, when the moon moves between the sun and the earth, the moon faces the earth with its dark side, and rises and falls with the sun, so people cannot see it. At this time, the moon phase is called "new moon" or "new moon".
After the new moon, the moon gradually moved out of the area between the earth and the sun. At this time, we began to see a small part of the moon illuminated by sunlight, which was shaped like a curved crescent, so the moon phase at this time was called "waning crescent moon". This "waning crescent moon" can only be seen in the western sky in the evening. By the eighth day of the lunar calendar, from the earth's point of view, the moon has moved to 9 degrees east of the sun. At this time, we can see the bright half of the west side of the moon. At this time, the moon phase is called "winding". The first quarter moon can only be seen in the first half of the night, and then it disappears into the west at midnight. After the first winding, the moon becomes full day by day, and we can see most of the bright hemisphere of the moon. At this time, the moon phase is called "convex moon".
On the 15th and 16th day of the lunar calendar, the moon moves on the celestial sphere directly opposite to the sun, and the distance between the sun and the moon is 18, that is, the earth is located between the sun and the moon. Seen from the earth, the whole light of the moon faces the earth, and the phase of the moon at this time is called "full moon" or "full moon". The full moon rises in the east at dusk and sets in the west at dawn.
After the full moon, as the positions of the sun and the moon get closer, the moon becomes thinner. It went through the stages of the convex moon, the last quarter moon and the waning crescent moon in turn, and finally returned to the position of the new moon.
waning crescent moon in the second half of the month is customarily called "the waning moon" in China.
The first quarter moon and the second quarter moon, waning crescent moon and Canyue are similar in appearance, but their appearance time, position and bright direction are different. Waning crescent moon and the first quarter moon appear in the western sky in the evening and the first half of the night respectively, and their "faces" are facing west, that is, the western half is bright; The waning moon and the last quarter moon appear in the eastern sky at dawn and after midnight respectively, and their "faces" are facing east, that is, the eastern half is bright. Because the date of Chinese lunar calendar is arranged according to the moon phase, the working people in ancient China sometimes rely on it to judge the date of Chinese lunar calendar and the approximate time of night.
It takes an average of 29.53 days for the moon to move from the new moon position to return to the new moon position again, that is to say, the average change period of the moon phase is 29.53 days, which is called a "shuowangyue".
1. Several mysteries of the moon
Mystery of the origin of the moon: At present, human beings have put forward three hypotheses about the origin of the moon, namely, the theory that the moon was captured, the theory that the earth and the moon are homologous, and the theory that the earth split. So far, the three hypotheses have not obtained strong evidence, so the fourth hypothesis "Moon"
The mystery of the moon's age: rock samples brought back from the moon can be used to determine the moon's age. It is found that 99% of the moon rocks are older than 9% of the oldest rocks on the earth. In 1973, a moon rock was determined to be 5.3 billion years old at the World Moon Symposium, while the oldest rock on earth was 3.7 billion years old. Some scientists suggest that the moon was formed in interstellar space long before the formation of the earth.
In addition, there are mysteries about the formation of craters on the moon, the age of lunar soil is older than the age of rocks, the loud noise caused by the impact of the moon, the stainless iron on the moon, and the large amount of water vapor on the dry moon.
Second, according to many documents, the moon did not exist since ancient times.
● The Maya in ancient America left a very developed culture, but in their Chronicle, which began before the flood, people were surprised to find that there was no record of the moon in it.
● About 4, years ago, the first curator of Alexandria Library wrote in his literature: "In ancient times, the moon was invisible in the sky of the earth."
● A very surprising piece of information is recorded in The History of the Jin Dynasty: "In the eleventh year of Taizong Tianhui, it was ugly in October and May, and the moon suddenly lost its way to the south, and it returned to the south in a moment." Meaning: In the 11th year of Emperor Taizong of Jin Dynasty (A.D. 1133), on May (June in Gregorian calendar), the moon suddenly deviated from its orbit, headed south, and soon returned to its original orbit.
Third, myths and legends related to the moon
● China's myths about the moon were first recorded in ancient books such as Shan Hai Jing, Chu Ci and Huai Nan Zi.
● There are many legends and fairy tales about the moon. There are stories about the Goddess Chang'e flying to the moon and Zhu Yuanzhang's anti-Yuan uprising.
● It is said that there is a laurel tree with a height of 5 feet in the moon. In the Han Dynasty, there was a man named WU GANG, who was obsessed with fairy tales and didn't concentrate on his studies. He was banished to the moon to cut laurel, but the laurel was cut with it, so later generations could see the image of WU GANG cutting laurel endlessly in the middle of the month.
IV. Fantasy poems about the moon in ancient China
● What is the virtue of luminous, and what is the fertility after death? What's the use of Jue Liwei, while Gu Rabbit is in the abdomen? (Qu Yuan's "The Songs of the South")
(Meaning: What are the characteristics of the moon, and when it dies, it grows again? What's the advantage of raising a rabbit in your arms? )
● Although the moon is in the middle of the month, there should be more clear light. (Du Fu's "One Hundred and Fifty Nights to the Moon")
● The old rabbit cries the sky, and the cloud floor is half-open and the wall is inclined white. The jade wheel rolled with dew wet around the light and shadow, the Osmanthus Alley mo Yan once met with the fairy - io of the Luan. (Li He's Dream of Heaven)
● Poor this evening and the moon, where are you going, where are you going? Don't ask, I'll see you there, east of light and shadow? Is it outside the sky, empty and sweaty, but the wind is mighty to send the Mid-Autumn Festival? It is like a mirror flying into the sky, but will not fall down, is it who uses an invisible long rope to fasten it? Chang' e in the moon palace is not married until now, and who has kept her? I heard that the moon swam the bottom of the sea, but there was no way to look at the cause. it was an unpredictable thing, and it was a terrible thing to worry about. I am afraid that the long whale in the sea will hit the yudianqiong building in the moon palace. Month from the bottom of the sea, the water will not worry about the water, but the rabbit has ever learned to swim? If the Tao is intact, why is the cloud gradually like a hook? (Xin Qiji's "Magnolia Slow")
5. Appreciating the moon is a good match
● Every month is bright, and August is particularly special; Mountains and mountains show, Wushan Mountain Xiu Xiu is very.
● Enjoy the moon in the Mid-Autumn Festival, the sky is full and the moon is absent; A wanderer is homesick, but his hometown is sweet.
● There is a full moon in the sky, half a month on earth, and the full moon meets half a month; Tonight is the end of the year, tomorrow is the year, and year after year is the end of the year.
● The Big Dipper is 14 o'clock underwater; There is a wild goose in the south building, and a pair of flies with shadows in the middle of the month.
● The building is high, but Ren Yunfei passed it; Small pool can send the moon.
● flowers are everywhere in the shadows; A pavilion of mountains, mountains, colors and moons peep at people.
● The water depends on the temperature, and the source of the stream is not found. The song is in the oblique light, and the lakeside scenery is available to everyone; Since the moon is full, Mo Wen by the pavilion will take the first photo at the beginning of the year and raise a glass to invite this evening. Does Chang 'e in the sky recognize me?
VI. The laudatory name and nickname of the moon
Jade Rabbit, Luminous, Su E, Ice Wheel, Jade Wheel, Jade Toad, Gu Rabbit, Chanjuan, Jade Bow, Jade Gui, Jade Plate, Jade Hook, Jade Mirror, Ice Mirror, Guanghan Palace, Chang 'e, Jade Sheep, etc.
VII. Legend of the moon's alien civilization
Legend has it that Armstrong, who landed on the moon, was suddenly surprised when he contacted the command center code-named Houston: "These things are amazing! Oh, my god It's unbelievable. I want to tell you that there are other spaceships here. They are arranged on the other side of the crater. They are on the moon. They are watching us ... "At this time, the telecommunication signal suddenly stopped. What did Armstrong see?
● On December 21st, 1968, the United States launched the first spacecraft to the moon at the Kennedy Space Center. After the spacecraft entered the lunar orbit, astronauts took the first photo of the back of the moon with a telescope camera at an altitude of 1 kilometers. Many years later, when people were studying these photos, they accidentally found that there was a huge circular object in the crater. It was very regular, unlike a natural thing, and it looked as if it was landing or taking off.
● Since Apollo 8, no.1, no.11, no.16 and no.17 have witnessed or photographed UFOs on the lunar surface. Even as early as 1966, the American Lunar Orbiter No.2 discovered that there were some tower-shaped buildings with a height of 12-23 meters on the lunar surface, and later, the spacecraft of the former Soviet Union also discovered these buildings.
Reference: Treasure House of Natural Science (Sun, Moon and Planet Volume).