The image of the moon (16) is a complete celestial body. The moon is about 7 billion years old. Like the earth, the moon has a layered structure such as shell, mantle and core. The average thickness of the outermost lunar shell is about 60-65 kilometers. Below the lunar crust to the depth of 1000 km is the lunar mantle, which occupies most of the volume of the moon. Below the moon's mantle is the moon's core, whose temperature is about 1000 degrees, which is likely to be in a molten state. The moon is about 3476 kilometers in diameter, which is 1/4 of the diameter of the earth and 1/400 of the diameter of the sun. The distance from the moon to the earth is equivalent to 1/400 of the distance from the earth, so the moon is as big as the sun. The volume of the moon is only 1/49 of that of the earth, and its mass is about 735 billion tons, which is equivalent to about 1/80 of the mass of the earth. The gravity on the surface of the moon is about 1/6 of that of the earth. The moon is the only natural satellite of the earth and the closest celestial body to the earth. Its average distance from the earth is about 384,406,5438+0 km. Its average diameter is about 3476 kilometers, slightly larger than the earth's diameter 1/4. The surface area of the moon is 38 million square kilometers. Although it is big, it is not as big as Asia. The orbit of the moon The moon orbits the earth in an elliptical orbit. The great circle cut by this orbital plane on the celestial sphere is called "White Road". The ecliptic plane is neither coincident with the celestial equator nor parallel to the ecliptic plane, and its spatial position is constantly changing. Rotation period, 27.32. The lowest surface temperature is-183 degrees Celsius.

Edit this synchronous rotation

The rotation of the moon and the simultaneous rotation around the earth have a period of 27.438+066 days, which happens to be a sidereal moon, so we can't see the back of the moon. We call this phenomenon "synchronous rotation", which is almost a universal law in the satellite world. It is generally believed that it is the result of the long-term tidal action of planets on satellites. The libration is a wonderful phenomenon, which enables us to see 59% of the moon. The main reasons are as follows: 1. In different parts of the elliptical orbit, the rotation speed does not match the revolution angular speed. 2. The intersection of the white road and the equator.

Edit this lunar terrain.

The name of the crater is

"Galileo"

Call it. It is a remarkable feature of the lunar surface, covering almost the whole lunar surface. The largest crater is Bailey crater near the South Pole, with a diameter of 295 kilometers, which is a little larger than Hainan Island. A small crater may even be a hole of dozens of centimeters. There are about 33,000 with a diameter of not less than 65,438+000m m. It accounts for 7- 10% of the lunar area.

On the surface of the moon (1 1), Japanese scholar 1969 put forward the classification of craters, which can be divided into Cravian type (ancient craters are generally unrecognizable, and some craters contain mountains) Copernican type (young craters often have "radiation patterns", with concentric hills on their inner walls and centers. The dark part of the moon seen by the naked eye is actually a vast plain on the moon. Due to historical reasons, this misnamed name has been preserved to this day. There are 22 moon seas identified, and some landforms are called "Moon Lake" or "Moon-like Sea". Most of the 22 recognized ones are distributed on the front of the moon. Three in the back and four on the side. On the front, the area of the Moon Sea is slightly over 50%, of which the largest "storm sea" covers an area of about 5 million square kilometers, almost the total area of nine French countries. Most of the moon seas are generally round and oval, and most of them are surrounded by some mountains, but some seas are connected together. Besides the sea, there are five lakes with similar topography-Hu Meng, Dead Lake, Fox Xia, Qiuhu and Chun Hu, but some lakes are bigger than the sea. For example, Hu Meng covers an area of 70,000 square kilometers, which is much larger than Qihai. The parts of the moon and the ocean that extend to the land are called "bays" and "swamps", and they are both distributed on the front. There are five bays: Luwan, Xiawan, Central Bay, Hongwan and Yue Mei Bay. There are three kinds of marshes: humus, epidemic marshes and dream marshes. Actually, there is no difference between a swamp and a bay. The topography of the Moon Sea is generally low, similar to the basins on the earth. The moon sea is1-2km lower than the average moon horizon, and the southeast of the lowest sea is even 6000m lower than its surroundings. The albedo of the moon (a physical quantity to measure the ability to reflect sunlight) is also relatively low, so it looks darker now. The land and mountains on the moon are called the moon land, which is generally 2-3 kilometers above the horizon of the moon sea. Because of the high albedo, it looks brighter. On the front of the moon, the land of the moon is roughly equal to the ocean of the moon. There are many sunken pits on the moon, which reflect light.

The three-dimensional animated image of the moon taken by Chang 'e-1, but on the back of the moon, the land area of the moon is much larger than the ocean area of the moon. Isotope determination shows that the moon and land are much older than the moon and ocean, and they are the oldest landforms on the moon. On the moon, in addition to many craters, there are some mountains similar to those on the earth. Mountains on the moon often borrow the names of mountains on the earth, such as Alps and Caucasus mountains. The longest mountain range is the Apennines, which stretches for 1000 km, but its height is only three or four kilometers higher than the moon horizon. There are also some steep peaks in the mountains, whose height was overestimated in the past. At present, it is believed that the heights of most peaks are similar to those of the earth, and the highest peaks (also near the south pole of the moon) are only 9000 meters and 8000 meters. On the moon, there are 6 peaks over 6000 meters, 20 at 5000-6000 meters, 80 at 4000-5000 meters, and 200 at 1000 meters. The mountains on the moon have a common feature: the slopes on both sides are asymmetrical, and the slopes on the seaward side are steep, sometimes cliff-shaped, while the other side is quite flat. In addition to the high mountains, there are four cliffs hundreds of kilometers long on the moon. Three of them stand out in the Moon Sea, also known as the "Moon Graben". Another main feature of the radiation pattern on the surface of the moon is that some young craters often have beautiful "radiation patterns", which is a bright belt extending in all directions with craters as the radiation point, and it passes through mountains, the moon sea and craters almost in a straight line. The length and brightness of radiation patterns are different, and the most striking one is the radiation pattern of Tycho crater. The longest one is 1800 km long, which is especially spectacular at the full moon. Secondly, Copernicus and Kepler craters also have quite beautiful radiation patterns. According to statistics, there are 50 craters with radiation patterns. The reason for the formation of radiation pattern is still inconclusive. Essentially, it is closely related to the theory of crater formation. At present, many people tend to say that meteorite impact may make high-temperature debris fly far on the moon, with no atmosphere and little gravity. Other scientists believe that the function of volcano is not ruled out, and the eruption of volcano may also form a flying radiation shape. The surface of the Moon Gap is very rough, covered with craters and craters.

There are many famous rift valleys on the earth, such as the Great Rift Valley in East Africa. There is also such a structure on the surface of the moon-those seemingly winding black cracks are the Moon Valley, and some extend for hundreds of meters to Qian Qian meters, with widths ranging from several kilometers to tens of kilometers. Most of those broad moon valleys appear on the flat land of the moon, while those narrow and narrow moon valleys (sometimes called moon streams) can be seen everywhere. The most famous Moon Valley is the alpine Moon Valley connecting Yuhai and Leng Hai, which is located in the southeast of Plato's crater. It cut off the Alps on the moon, which is very spectacular. The photos taken from space are estimated to be 130 km long and 10- 12 km wide. The moon itself revolves around the earth from west to east, so it should rise in the west and set in the east. However, because the earth's rotation direction is also from west to east, the actual visual effect is that the moon rises in the west and sets in the west.

Edit this material introduction.

Surface temperature (t) -233~ 123℃ (average -23℃) atmospheric pressure1.3×10-10 kpa moon variation.

The lunar sphere orbits the earth for about one lunar month, and moves half a degree relative to the background starry sky every hour, which is similar to the apparent diameter of the lunar surface. Unlike other satellites, the orbital plane of the moon is closer to the ecliptic plane than the equatorial plane of the earth. Relative to the background starry sky, the time required for the moon to go around the earth (the moon makes one revolution) is called sidereal month; The time between the new moon and the next one (or the time between two identical moon phases) is called the new moon. The reason why Wang Shuo's moon is longer than that of the star moon is that during the earth's operation on the moon, it moved forward a certain distance in its orbit around the sun. The orbit plane of the moon (ecliptic plane) keeps an included angle of 5. 145396 with the ecliptic plane (earth's orbit plane), while the rotation axis of the moon forms an included angle of 1.5424 with the normal of the ecliptic plane. Because the earth is not a perfect sphere, but bulges at the equator, the white road surface keeps precessing (that is, the intersection with the ecliptic rotates clockwise) and completes one week every 6793.5 days (18.5966). During this period, the angle between the white plane and the equatorial plane of the earth (the equatorial plane of the earth inclines to the ecliptic plane at 23.45) will change from 28.60 (i.e. 23.45+5. 15) to18.30 (i.e. 23.45-5. 15). Similarly, the angle between the rotation axis of the moon and the white plane will be between 6.69 (that is, 5. 15+ 1.54) and 3.60 (that is, 5. 15- 1.54). These changes in the lunar orbit will in turn affect the inclination of the earth's rotation axis, making it swing by 0.002 56, which is called nutation. The two intersections between the ecliptic plane and the ecliptic plane are called the lunar intersection-the ascending intersection (north point) refers to the point where the moon passes to the north of the ecliptic plane; Descending node (South Point) refers to the point where the moon passes south of the ecliptic. When the new moon is just at the intersection of the moon, a solar eclipse will occur; An eclipse occurs when the full moon is just at the intersection of the moons. There will be a shadow on the earth far away from the sun, which is called the earth shadow. The shadow of the earth is divided into umbra and umbra. The penumbra is divided into two parts. The umbra refers to a place that is not exposed to direct sunlight, while the penumbra is only exposed to some direct sunlight. In the process of orbiting the earth, the moon sometimes enters the shadow of the earth, resulting in an eclipse. When the whole moon enters the umbra, a total lunar eclipse will occur; But if only a part of it enters the umbra, only a partial lunar eclipse will occur. During the total lunar eclipse, the moon is not completely invisible, because sunlight will be refracted into the umbra when it passes through the thin atmosphere of the earth, and projected onto the surface of the moon until the surface of the moon appears red and copper.

Edit the basic features of this paragraph.

Gradually away from the earth

The moon moves away from the earth at a speed of 3 cm per year. A billion years ago, it was only half as long as it is now. The moon is now about 60 times from the earth, which is the radius of the earth. However, due to the influence of tidal force between the Earth and the Moon, the Moon is slowly leaving the Earth at a speed of about 3 cm per year. On the other hand, the rotation speed of the earth is also gradually slowing down. That is to say, at that time, the moon was closer to the earth than it is now, and the earth rotated faster than it is now.

The evidence of the panoramic view of the moon (6 photos) lies in the fossils of "two kinds of shellfish" discovered by scientists. The growth speed of the two kinds of shellfish will change with the fluctuation of tide, and stripes similar to tree rings will be formed while growing, and the number and width of stripes will vary according to the humidity. According to the number and width of these articles, scientists found that about 500 million years ago, the earth had only 2 1 hour a day and 4 1 day a year.

Lunar structure

Guess the moon may be hollow. The moon is an ice planet. It may be attracted by the earth when it passes by, so it has an orbit. When exploring the moon, it was found that when attracted by the earth, the surface cracked and the water tilted outward, which led to the "Noah flood" of the earth. Later, the moon nucleus filled the crack and the moon became nuclear-free. Moreover, the average density of the moon is smaller than that of the earth, indicating that there is a lot of air inside the moon. However, this theory needs further study.

Moving moon phase

Definition of Moon Phase As the moon moves a long distance from west to east in the starry sky every day, its shape is constantly changing. This is the phase change of the moon, called the moon phase. In astronomy, the moon phase refers to the part of the moon that is illuminated by the sun as seen from the earth. Lunar phase change

[1] The cause of the moon phase is that the moon shines by reflecting sunlight, which is different from the relative position of the sun (the difference of the ecliptic), so it will take on various shapes. As shown in the figure, at position A, the longitude difference between the sun and the moon is 0, which is called new moon or new moon. At this time, the moon faces the earth with its dark side, and appears almost at the same time as the sun, so it can't be seen on the ground. At point C, the longitude difference of 90 degrees is called winding, and a half moon appears in the western night sky in the middle of the night; At point E, the longitude difference of the meridian is 180, that is, the full moon, and a full moon can be seen all night; G is the bottom chord, and the longitude difference is 270. At this time, the half moon only appears in the eastern half of the sky at midnight. The profit and loss cycle is called the new moon, which is about 29.5059 days long. The movement of the moon The rotation of the moon around the earth is called the revolution of the moon. The moon moves from west to east, and its orbit is elliptical like all celestial bodies. The point closest to the earth is called perigee, and the point farthest from the earth is called apogee. The evidence that the moon moves westward is that every time it sets westward, it is delayed by an average of 49 minutes. Compared with the star, its movement period is about 27.3 days, that is, during this time, it runs in space for 3600 years; But at the same time, the earth keeps going around the sun, so the moon should complete a phase cycle, that is, more than two days from the new moon, which is about 29.53 days. Therefore, the movement period of the moon's stars is about 27.3 days, which is called the sidereal moon; The relative movement period of the sun-earth link is about 29.53 days, which is called the first lunar month. The moon is the foundation of the moon. The surface of the moon is made of rocks and dust. It doesn't shine itself, just like the earth, so the moon phase we see is the part of the moon that reflects sunlight. Starting from the new moon, the phase change order of a lunar month is: new moon, first quarter moon, hope moon and last quarter moon. In the lunar month, the time from the new moon is called the monthly order, such as 14 days. Before and after the new moon, the sunshine surface of the moon seen from the earth is crescent-shaped, and half a moon wheel can be seen when it is bent, while before and after the moon, the sunshine part of the moon is convex. The first quarter moon is different from the last quarter moon because when it bends, it is located in the western half of its moon wheel when viewed from the earth, and when it bends, it is located in the eastern half.

Orbit around the moon

The moon revolves around the star once (constant week), and the period relative to the star is 27.32 days. However, because the earth revolves around the sun at the same time, it will take a long time to show the same phase to the earth, about 29.53 days (its rendezvous period). Unlike most satellites of other planets, the orbit of the moon is closer to the ecliptic plane than the equatorial plane of the earth. The orbit of the moon is disturbed by many tiny, complex and interactive disturbances between the sun and the earth, such as the gradual rotation of the lunar orbital plane, which affects other motion states of the moon. Cassini's law mathematically describes the subsequent influence. The orbit of the moon around the earth

Among them, the main trajectory changes are: eccentricity change, trajectory inclination change, arch line movement, intersection point retreating westward and center difference.

Orbit change