Geographical structure map of senior one

Analysis of compulsory map of geography in senior one.

Figure 1. 1 The universe is made of matter.

This is a schematic diagram showing that the universe is made up of matter and consists of four small pictures. From top to bottom, there are Crab Nebula, Saturn, Leonid Meteor Shower and Comet Ha. The image of the picture is intuitive, which increases the realism and credibility of the universe composed of matter.

When reading the schematic diagram of "the universe is composed of matter", we should pay attention to its rich connotation and extension, and reveal to students one by one according to our own teaching practice, such as what is the universe, celestial bodies, planets, meteoroids, nebulae, comets and so on. The schematic diagram of "the universe is made up of matter" becomes rich and interesting from a single understanding of several substances that make up the universe, and stimulates students' learning enthusiasm and exploration spirit.

The steps to read the schematic diagram of "The universe is made of matter" are as follows:

① Explain the purpose of reading pictures.

The purpose of reading pictures is to know that the universe is made of matter. The content shown in the picture is a part of the matter that makes up the universe, commonly known as celestial bodies. The figure only shows the shape of each celestial body, not their height and mutual position in space. It is an independent schematic diagram of the shape of each celestial body.

② Explain the related concepts involved in the diagram.

Universe: Ancient scholars in China said that "the universe is everywhere, and the universe is everywhere, which is a metaphor for heaven and earth". It means that space refers to infinite space and the universe refers to infinite time. The universe is a material world with boundless space, no beginning and no end in time, and constantly moving according to objective laws. It is the floorboard of all things in the world. The universe is diverse and unified, and diversity refers to the diversity of material expressions in the universe, such as the diversity of various celestial bodies; Unity is manifested in the fact that the universe is made of matter. All kinds of substances that make up the universe have their processes of occurrence, development, evolution and extinction, and they are all limited; As a whole, the universe is infinite in the transformation of time and space and the form of material movement. Therefore, the universe is made of matter, and matter is in motion.

Celestial body: the general name of all kinds of stars in the universe. There are two kinds of natural celestial bodies and artificial celestial bodies. Stars, planets, satellites, meteoroids, comets and nebulae are all natural celestial bodies. Satellites are artificial celestial bodies.

Crab nebula: It is a famous gas nebula in the Milky Way, which has quite strong radio sources, infrared source, X-ray sources and γ-ray sources. Located in the northwest of Taurus ξ star (called "Tiangong" star in China) 1. Orion, Sagittarius, Lyra and Fox are several bright star clouds in the sky, and the scattered nebula of Orion can be seen by naked eyes.

Saturn: One of the nine planets in the solar system, it is the sixth star and has 23 natural satellites, arranged according to the distance from the sun. Its atmosphere is very thick, mainly composed of methane and a small amount of ammonia. The cloud band on its surface is more regular than Jupiter, but not as obvious as Jupiter. On its equatorial plane, it is surrounded by a beautiful flat and broad halo, which is composed of countless particles, all of which revolve around Saturn. The halo has a diameter of over 270,000 kilometers, a width of about 94,000 kilometers and a thin thickness of less than 20 kilometers. The halo is not complete, it is separated by a number of dark seams and becomes several rings. Saturn's sixth satellite, larger than Mercury, has an atmosphere on its surface, which is unique among many satellites of nine planets in the solar system. In ancient China, Saturn was called "filling star" and "town star".

Meteor: Small dark dust particles and solid matter in interplanetary space. When it breaks into the earth's atmosphere, it rubs violently with the atmosphere and emits light, producing a short and bright light trace, which is called a meteor. Meteors are divided into accidental meteors and meteor groups. Occasional meteors are single, sporadic and unrelated, and their time and direction are irregular. Generally, there are more meteors and brighter in the middle of the night than in the middle of the night. Meteor cluster refers to the characteristic meteor cluster that gathers in the same orbit and rotates around the sun. They may be fragments of the comet after disintegration, which are unevenly distributed in the orbit. When the earth meets the dense parts of these meteors, meteors radiate from a certain point in the sky as if it were raining. People call this phenomenon "meteor shower". Compared with other constellations, Perseus and Leo have more "meteor showers" and are famous meteor group constellations. Meteor is a phenomenon that occurs in the atmosphere from 80 km to 120 km above the ground. Meteor phenomenon is not only related to the meteor itself, but also to the atmosphere. Through the observation of meteors, we can understand the physical situation of the atmosphere.

Halley's Comet: Comet is a small celestial body like a cloud, with very small mass and running in a flat orbit. In memory of the British astronomer Halley, the comet was named Halley's comet for the first time by using the law of universal gravitation to calculate its orbit and predict its orbit around the sun in a period of 76 years. As the picture shows, a comet consists of a head and a tail. The head of a comet includes a nucleus, a coma and a coma cloud. The nucleus of a coma is composed of relatively dense solid blocks and particles, and the cloud-like light around it is called coma, and the hydrogen atom cloud is distributed around the head of the coma. The material at the tail of the comet, under the radiation pressure of the solar wind, extends away from the sun and is shaped like a broom. Therefore, comets are commonly known as broom stars, which were called "demon stars" in ancient China. Comets have three orbits: ellipse, parabola and hyperbola. Comets with parabolic and hyperbolic orbits are aperiodic comets. They turned a corner around the sun and never came back. They can only be seen once. Comets with elliptical orbits always orbit the sun periodically, called periodic comets, which can be seen many times, such as Halley's Comet. Most comets and planets orbit the sun in the same direction, which is anterograde. However, there are exceptions. For example, Halley's comet is called a retrograde comet because it runs in a different direction from the planet around the sun. China is the country with the earliest and richest record of Halley's Comet. Halley's comet was first recorded in 6 13 BC, and the observation record of Halley's comet was in Europe in 1 1 BC.

■ Figure 1.2 Different levels of celestial bodies in the universe

This picture not only shows that the universe is made up of matter, but also further reveals the subordinate relationship between matter. The existence of this subordination depends on the fact that the substances are in motion, and the moving substances attract each other and form their own groups respectively. Small groups belong to large groups, and large groups belong to larger groups, forming a vast universe.

Arrows are used to indicate the affiliation of celestial bodies at different levels in the universe. Below the picture is a celestial system consisting of the Earth and its natural satellite, the Moon, with the Earth as its central celestial body. Because the mass difference between the earth and the moon is very large, reaching the ratio of 865,438+0: 65,438+0, according to the law of universal gravitation, there is mutual attraction between two objects due to the mass of matter, and the object with large mass has great attraction to the object with small mass. This is the reason why the moon and artificial satellites orbit the earth. Due to the great difference in mass between the earth and the moon, the center of mass of the earth-moon system is only 4728 kilometers away from the center of the earth, which is about 1.650 kilometers underground. Generally speaking, the revolution of the moon around the earth is actually the revolution of the earth and the moon equivalent to their concentric centers.

The arrow of earth-moon system in the picture points directly at the solar system, staying at the position of the earth and their affiliation. The solar system is a celestial system centered on the sun, and gravity connects all the celestial bodies in the system. The solar system is generally a sphere with a radius greater than 100000 astronomical unit (one astronomical unit = average distance between the sun and the earth = 1.4960× 108km). The sun is the main body of this system, accounting for 99.86% of the total mass of the solar system. The solar system includes the sun and nine planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto), 2958 officially numbered asteroids, 48 satellites, and many comets and meteoroids. Geochemical dating shows that the earth and the whole solar system were separated from a certain part of the Milky Way 4.7 billion years ago.

The arrow of the solar system in the picture points directly at the Milky Way and stays in the position of the solar system in the Milky Way, which clearly tells us the position of the solar system in the Milky Way and the subordinate relationship between the two. The Milky Way is the celestial system where the earth and the sun are located, and the projection of this celestial system on the celestial sphere is the Milky Way we see at night. The Milky Way is a spiral galaxy, consisting of two spiral arms, which are 4500 light years apart. The Milky Way includes more than 200 billion stars and a large number of nebulae, interstellar gas and interstellar dust. Its total mass is 654.38+04 billion times that of the sun, of which 5% ~ 654.38+00% is gas and dust. Most stars are concentrated in an oblate space, which is shaped like a discus. Some stars are sparsely distributed in a spherical space called "silver halo". The center of the Milky Way galaxy is about1.200 million light years thick, in the direction of Sagittarius. The sun is about 33,000 light years from the center. The whole galaxy is rotating, and the rotation speed and period of each part are different because of the different distances from the center of the galaxy. The rotation speed of the sun is 250 km/s, and it takes about 250 million years for the sun to circle the center of the Milky Way.

In the figure, the arrow of the galaxy map points directly at the total galaxy and stays at the position of the galaxy, which clearly tells us the position of the galaxy in the universe and the subordinate relationship between the galaxy and the total galaxy. A celestial system consisting of billions to hundreds of billions of stars, interstellar gas, dust and other substances is called a galaxy, and the Milky Way is an ordinary galaxy. Galaxies outside the Milky Way are called extragalactic galaxies. At present, there are about10 billion extragalactic galaxies that can be observed. According to their shapes, they can be divided into five major galaxies: elliptical galaxies, lens galaxies, spiral galaxies, rod spiral galaxies and irregular galaxies. Andromeda galaxy and small Magellanic galaxy can be seen with naked eyes. Andromeda galaxy is the largest spiral galaxy nearest to us. Large and small Magellanic galaxies can be seen over Nansha Islands in China. They are two celestial bodies similar to clouds. Astronomically, the Milky Way and the extragalactic galaxies that can be observed at this stage are called total galaxies. The total galaxy is the universe we can observe.

■ Figure 1.3 Earth's position in the solar system

This is a close-up of the solar system, which is the most common and commonly used image in geography books. It is the image that appears more in various geographical examinations and gives higher marks; It is also the key image of geography teaching in senior one, which shows the cosmic environment of the earth; It is also the key image of the textbook in this section. Together with the figures 1. 1 and 1.2, the exact position of the earth in the universe is expressed from far and near, and the hierarchical requirements of knowledge education are fulfilled. Among the three pictures, this picture is the landing place of key knowledge, which plays the role of connecting the past with the future and is very important.

Looking at this picture, we should closely follow the text description in the book and the data description in the table 1. 1. The levels are as follows: ① the correctness of "Heliocentrism". In the 3rd century BC, the ancient Greek astronomer Aristak proposed "Heliocentrism". He thinks that the sun is the center of the universe, and the earth and other planets revolve around it. Later, Ptolemy, an astronomer, mathematician, geographer and cartographer in ancient Greece, put forward the geocentric system in his main work, The Theory of Great Synthesis. He claims that the earth occupies the central position, and the sun, moon, planets and stars all revolve around the earth, which is called "geocentric theory". This theory has been used by Christian theology and has been dominant for a long time. It was not until Copernicus published Heliocentrism that the geocentric theory was overthrown. It dealt a heavy blow to theocracy and caused a revolution in world outlook. Copernicus was a Polish astronomer. His greatest achievement is to use the scientific "Heliocentrism" to deny the geocentric theory and liberate natural science from theology. The picture on the previous page vividly reflects Copernicus and Heliocentrism's cosmic system. Copernicus believed that the sun was the center of the universe, and other planets and stars revolved around the sun in a "perfect" circular orbit. In fact, the sun is the center of the solar system, not the center of the universe. With the progress of the times and the development of science, Heliocentrism was founded on a more solid scientific basis after Kepler summed up the three laws of planetary motion and Newton discovered the law of universal gravitation. ② The earth is an ordinary planet in the solar system. First, guide the students to find the earth in the picture, tell the neighbors of the earth and determine the position of the earth in the solar system. Secondly, with reference to table 1. 1, the mass, volume, average density, rotation and revolution of the earth are compared with other planets, and it is concluded that the earth is an ordinary planet in the solar system, highlighting its generality. The earth is a special planet in the solar system. First, guide the students to analyze the shapes of planetary orbits in the picture, and get that their orbits are quite close to the circle (approximate circle). Secondly, read the arrows in the revolution direction of the nine planets, and get the characteristics that they are in the same direction around the sun. On this basis, the teacher said that the orbital planes of the nine planets around the sun are almost on the same plane, that is, the * * * plane. Because the nine planets revolve around the sun with the characteristics of * * * areal, isotropic and nearly circular, the earth is in a relatively safe cosmic environment. Finally, the reason why the earth is alive is explained from the distance between the sun and the earth, the volume and mass of the earth and the change of the earth. Highlight its particularity.

■ Figure 1.4 Solar radiation and solar constant

Starting with the concepts of solar radiation, solar constant and the distance between the sun and the earth, this picture shows that solar radiation is the energy source on the earth. The steps to read the chart "Solar Radiation and Solar Constant" are as follows:

① Explain the structure of the map sheet.

② Explain the related concepts in the diagram.

Sun: The sun is the most striking celestial body in the sky. It is a star in the center of the solar system. Its apparent magnitude is -26.78 (the magnitude divided according to the amount of star light received on the earth is called "apparent magnitude", and its brightness decreases with the increase of magnitude. The zero-magnitude star is brighter than the first-magnitude star and the negative-magnitude star is brighter than the zero-magnitude star), which is 500,000 times brighter than the moon (the apparent magnitude of the moon is -65438). The diameter of the sun is 654.38+0.39 million kilometers, which is 654.38+0.09 times that of the earth and 400 times that of the moon. The volume of the sun is 6.5438+0.3 million times that of the earth, the mass is 330,000 times that of the earth, and the average density is 654.38+0.4 g/cm3. The weight of the sun is 270 times that of the moon. Compared with the moon, the sun is like an elephant and an ant. The distance between the sun and the earth is10.50 billion kilometers, which is 400 times of the distance between the moon and the earth. The sun is a hot air balloon, and the temperature is getting higher and higher from the surface to the center. The central area is about160,000℃ and 300 billion atmospheres. At the center of high temperature and high pressure, a huge nuclear reaction area is formed, which is composed of hydrogen and helium. When hydrogen is converted into helium, it can release huge energy, which is nuclear fusion reaction. The energy released in the nuclear fusion reaction radiates around in the form of electromagnetic waves, which is commonly called solar radiation. Five billion years ago, since the formation of the sun, it has continuously released enormous energy, and it is estimated that this state will continue for another five billion years. Visible to the naked eye, the surface layer of the sun is the photosphere, the periphery of the photosphere is the chromosphere, and the outermost layer is the corona, which constitutes the atmosphere of the sun. The sun also rotates and revolves. The rotation period is about 25 days in equatorial belt and 35 days in dual-machine area. The period of revolution (the period around the center of the Milky Way) is about 250 million years (assuming the orbital eccentricity is zero).

The solar constant in the figure represents the physical quantity of solar radiation energy. The meaning of this physical quantity is that when the solar radiation reaches the upper boundary of the earth's atmosphere, that is, one astronomical unit (the distance between the sun and the earth) away from the sun, the radiation energy obtained in 1 minute on the area perpendicular to the sun's rays is usually in the unit of card/cm 2 minutes or Joule/cm 2 minutes. The sun constant is not an absolute constant. It may change by 3.5% due to the change of the distance between the sun and the earth, or it may change by 65438 0.5% due to the diurnal change of solar physical conditions and the periodic activities of the sun. When solar radiation passes through the earth's atmosphere, due to the weakening of absorption, scattering and reflection, the direct solar radiation reaching the earth's surface is greatly weakened, and for most areas of the earth, it will not exceed 1.5 calories/cm2. The solar radiation energy reaching the earth is only equivalent to1/2.2 billion of the solar radiation energy. The energy obtained by the earth from the sun in one year is equivalent to tens of thousands of times that provided by various energy sources in the same period. Some natural gas energy on the earth may be exhausted one day, but solar energy is inexhaustible clean energy. The earth also gets energy from the moon and other celestial bodies, but the amount is negligible. For example, the energy obtained by the earth from the moon and other celestial bodies is only 1% of the solar radiation energy; The radiant energy from space is only1/2 of the solar radiation; The energy transmitted from the earth's interior to the ground is only one tenth of the solar radiation energy. Therefore, solar radiation is the most important energy source of the earth, the most fundamental driving force for various phenomena and evolution in the atmosphere, and the extremely important factor for the formation and change of geographical environment. Solar radiation is the most important influence of the sun on the earth and the source of life on the earth.

■ Figure 1.5 Annual solar radiation distribution map of China.

Solar energy has great potential. In order to facilitate the development and utilization of solar energy resources, the utilization of solar energy resources in China is divided according to the following indicators: first, the annual total solar radiation, and second, the number of days when the monthly average temperature is ≥ 10℃ and the sunshine hours are ≥6 hours. According to this standard, China is divided into areas rich in solar energy resources, relatively rich areas, available areas and poor areas (see figure).

① Resource-rich areas: the annual total solar radiation is above 1700 kWh per square meter, and the sunshine hours are above 10℃ for more than 300 days. Mainly distributed in southern Xinjiang, Longxi, most of the Qinghai-Tibet Plateau and the western Inner Mongolia Plateau. Among them, the Qinghai-Tibet Plateau is a high-value center.

② Resource-rich areas: the annual total solar radiation is per square meter 1500 ~ 1700 kWh, and the number of days with sunshine hours ≥6 hours during the period of monthly average temperature ≥ 10℃ is 200 ~300 days. It is mainly distributed in northern Xinjiang, eastern Inner Mongolia Plateau, most of North China Plain, most of Loess Plateau, southern Gansu, western Sichuan and parts of southern Sichuan and northern Yunnan.

(3) Available area of resources: the annual total solar radiation is 1, 200 ~ 1, 500kWh/m2, the number of days with sunshine hours ≥6 hours during the period of monthly average temperature ≥ 10℃ is 1, and 25 ~200 days. It is mainly distributed in most parts of Northeast China, southeast hilly areas, Hanshui River Basin, most parts of Guangxi, parts of western Sichuan and western Guizhou, southeastern Yunnan and eastern Hunan.

④ Resource-poor areas: the annual total solar radiation is below 1.200 kWh per square meter, and the number of days with sunshine hours ≥6 hours during the period of monthly average temperature ≥ 10℃ is below 1.25 days. It is mainly distributed in most areas of Sichuan, Chongqing and Guizhou, with the least in Chengdu Plain.

In the teaching of reading pictures, students can be guided to complete the following tasks: a. Find out the four distribution areas of solar energy in China. B Analyze the reasons why solar energy-rich areas are rich in resources (high terrain, small thickness of solar radiation passing through the atmosphere, more sunny days, less precipitation, and less solar radiation weakened by the atmosphere). C, know the location of hometown, and analyze the prospect of using solar energy in hometown.

■ 1.6 solar atmospheric structure

In the vast universe, the sun is just an ordinary star in the Milky Way, but for the earth, it is different from ordinary stars, and its light and heat are the source of human survival and activities. Many natural phenomena on the earth are closely related to the sun. Because the distance between the sun and the earth is very close, the sun is the only star on the earth that can see the details of its surface. The exterior of the sun, that is, the solar atmosphere, can be divided into three layers from the inside out: the photosphere, the chromosphere and the corona. The photosphere is the innermost layer of the solar atmosphere, and the bright round surface that can be observed by the naked eye at ordinary times is the photosphere. The sunlight reaching the earth comes from this layer, with a thickness of about 500 kilometers and a temperature of about 6,000 K. chromosphere is the middle layer of the sun's atmosphere, located above the photosphere, which is a rose circle on the sun's circular surface. Only visible to the naked eye at all times, the thickness is about 2000 kilometers, and the temperature ranges from 5000℃ at the bottom to tens of thousands of degrees at the top. The corona layer is the outermost layer of the solar atmosphere, located above the chromosphere. It contains extremely thin particle density and is the transition zone between the solar atmosphere and interplanetary space. The total solar eclipse can only be seen by the naked eye, the thickness is several solar diameters, and the temperature is about 654.38+0 million to 2 million℃.

■ Figure 1.7 Sunspots, Figure 1.8 Variation process of a large flare, Figure 1.9 Correlation between sunspots and annual precipitation.

These three pictures illustrate the influence of solar activity on the earth. The reading steps are as follows:

(1) Explain the relevant knowledge in the picture.

(2) Summarize the three pictures and get the influence of solar activity on the earth.

Solar activity is the general name of all activities in the solar atmosphere, which is characterized by sunspots, sunspots, flares, spectral spots, prominence and radio changes. Solar activity is strong, weak and periodic. The abnormal change of weather and climate on the earth is related to the intensity and periodic change of solar activity, and the aurora, magnetosphere and ionosphere disturbance on the earth are also related to solar activity.

Sunspots are black spots that often appear in the photosphere. The number of sunspots reflects the strength of solar activity and is the basic symbol of solar activity. Sunspots look dark due to the contrast of bright photosphere, but they are still glowing. A large sunspot can emit light as bright as a full moon. There are large and small sunspots. The diameter of small sunspots is about 1000 km, and the diameter of large sunspots can reach 200,000 km. Sunspots are shaped like a shallow dish with a depression about 500 kilometers in the middle. Fully developed sunspots are divided into umbra and penumbra, as shown in figure 1.7. The distribution of sunspots on the sun's surface has certain rules. For example, whenever sunspots are observed, there are always more sunspots in the eastern half than in the western half, and the sunspots are basically distributed at the latitude of 8 degrees to 40 degrees on the surface of the sun. Most sunspots appear in groups, and each sunspot group consists of several to dozens of sunspots, up to more than 100. The active period of sunspots is 1 1 year. When large sunspot groups appear, there will be magnetic storms, auroras and ionospheric disturbances on the earth.

Flare refers to the sudden brightening of a certain area in chromosphere. Flares mostly appear in the sky near sunspots, and their life spans range from a few minutes to several hours, as shown in figure 1.8. The "change process of a flare" is only about 2 hours. There are more sunspots, and there are more opportunities for flares. When a flare appears, it throws a lot of high-energy electrons and protons, emits intense ultraviolet rays and X-rays, and has a series of radio phenomena. Ultraviolet rays and x-rays reach the upper atmosphere of the earth, destroying the normal state of the ionosphere and affecting short-wave radio communication. When particle radiation reaches the earth, it will cause geomagnetic disturbance, aurora and other phenomena. High-energy particles and short-wave radiation produced by flares are very harmful to manned spacecraft. Therefore, observatories all over the world often issue flare forecasts, and flare is the main symbol of solar activity.

After understanding the influence of solar activities on the ionosphere, magnetic field and aurora, guide students to read Figure 1.9, that is, the correlation between sunspots and annual precipitation, so that students can further realize that solar activities also have an impact on climate.

The stations in figure 1.9 are all in the northern hemisphere, from mid-latitude to high latitude. In the figure, the left ordinate is the annual average precipitation, the right ordinate is the relative number of sunspots, and the bottom abscissa is the time span of observation points, which is 80 years. The red curve in the figure is the change curve of sunspots in 80 years, and the blue curve is the change curve of annual average precipitation in the same period.

The correlation between the two color curves in the picture can be described as follows: ① During the 30 years from the end of last century to the beginning of this century, the annual precipitation of the earth was at the lowest value, that is, 30-40% less than usual, with less rain and dry climate, and the number of sunspots was inversely proportional to the annual precipitation. From 19 10, the annual precipitation of this observation point is also more in years with relatively more sunspots, which is in direct proportion. (2) The correlation between the two curves of 22 stations in the figure shows that when the number of sunspots is relatively large, the precipitation at the station will increase and the climate will be humid. The correlation between the two curves is inversely proportional. (3) From the observation data of the high latitude area 12 station in the figure, the changes of the valleys and peaks of the two color curves are basically the same, that is, in the year with relatively more sunspots, the precipitation at the measuring point also increases accordingly; In years with relatively few sunspots, the precipitation at the measuring point is also less. The correlation between the two curves is directly proportional. ④ From the analysis of the three maps, it can be concluded that the change period of sunspot number is basically consistent with the change period of annual average precipitation, which is about 1 1 year. This shows that there is a certain correlation between the change of sunspot number and annual average precipitation, that is, solar activity does affect the weather and climate on the earth. Why different latitudes have different correlations needs further demonstration by scientists. As a student, it is enough to understand these correlations qualitatively.

■ Diagram1.1Schematic diagram of the genesis of the moon phase, diagram1.1Moon phase change.

These two pictures show the relationship between tomorrow, the moon and the earth and the law of moon phase change. When guiding students to read drawings, the steps are as follows: ① Explain the drawing structure; ② Explain relevant knowledge; ③ Instruct students to observe the moon phase on the spot. Figure 1. 10 shows that the sun shines from the right, and the inner circle shows eight different positions of the moon in its orbit (it is always bright and dark, and the moon's profit and loss have not changed from space). The outer circle represents the moon's profit and loss changes from round to round on the earth in various positions.

In the figure 1. 10, the moon goes from A to B, C, D, and then back to A, completing a revolution around the earth. With the different position of the moon in the orbit of revolution, the positional relationship among the sun, the earth and the moon changes accordingly, and the moon phase appears every 3.7 days on average. Within one month of the lunar calendar, * * * appeared eight phases of the moon. When the moon is at point A, it is between the sun and the earth, and its dark side faces the earth, so the moon can't be seen on the earth. This is the first day of the lunar calendar, also known as the new moon. When the moon is at point B, it is 90 degrees east of the sun, on the side of the earth. At this time, half of its dark side and half of its bright side face the earth, and we see the half moon with its bright side facing west. This is the first quarter moon, which usually appears on the seventh or eighth day of the lunar calendar. When the moon is at point C, the earth is between the sun and the moon, and the moon is opposite to the sun. At this time, the side of the moon illuminated by the sun is all facing the earth, and we see a full moon. At this time, the moon phase is called the moon, which is equivalent to the fifteenth or sixteenth of the lunar calendar. When the moon is at point D, it is 90 degrees west of the sun and on the side of the earth. At this time, we see the half moon facing the east, which is the last quarter moon, just the opposite of the first quarter moon, and generally appears on the 22nd or 23rd day of the lunar calendar. Then the moon continued to move eastward, getting closer and closer to the sun, returning to the position of point A, and the moon phase gradually changed from the lower chord to the new moon. The moon goes from point A to point A through points B, C and D, and goes around the earth once. Because of the change of the position of the sun, the earth and the moon, the time interval that the moon goes through from one new moon to the next is called Wang Shuoyue, which is also the period of the moon's phase change.

Figure 1. 1 1 illustrates the corresponding relationship between the shape of the moon phase at different times and its position in the sky. In the first half of the lunar calendar, the moon is located in the east of the sun. It rises from the horizon before sunset and the sky appears, so there is a saying that "the moon has risen before sunset". The newborn moth-eyebrow moon often rises shortly after the sun rises and appears in the western sky after dusk. The bow of the new moon faces west, but it soon disappears into the western sky. In the first quarter of the moon, the moon rises at noon, around 18 appears in the southern sky, sets at midnight, and the bow arc faces west, which is visible at midnight. At the full moon, when the sun sets on the western horizon, the moon just rises from the eastern horizon and can be seen all night.

In the second half of the lunar calendar, the moon is called the waning moon, which turns from surplus to deficit. The waning moon is located in the west of the sun, and it doesn't set from the horizon until sunrise, so there is a saying that "the sun rises, but the moon doesn't set". In the first quarter of the moon, the moon appeared on the eastern horizon at 24 o'clock in the middle of the night, and set at noon, with an arcuate arc facing the east. The moth-eyebrow moon (waning moon) appeared in the eastern sky before dawn, and the crescent bow headed east, and soon disappeared in the eastern sky. As can be seen from the column of "Moonrise" in the cracked table below, the moon rises later every day, with an average delay of about 50 minutes from the previous day.

P. 10 The activity table in the textbook is used to observe the moon phase. Teachers should ask students to observe the moon phase continuously for one month from the beginning to the end of the lunar month, and check their own observation records. From the beginning of the month to the full moon, the moon phase can be observed as soon as the sun sets, and the moon phase and position can be recorded every day. From the full moon to the end of the month, you can observe the moon phase before the sun rises, and you can also record the moon phase and position. Then organize observers to hold a special class meeting on the moon to achieve the purpose of applying geographical knowledge to practical teaching.