The change in the size of the moon is detailed, and what is the reason for the change of the moon

On the first day of the lunar month, 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. The phase of the moon at this time is called the "new moon" or "new moon".

After the new moon, the moon gradually moves out of the area between the earth and the sun, and then we begin to see a small part of the moon illuminated by the sun, like a curved eyebrow, so the moon phase at this time is called "the moon of the eyebrow". This "crescent moon" can only be seen in the western sky in the evening.

Around the eighth day of the lunar calendar, the moon has moved to a 90° angle east of the sun as seen from the earth. At this time, we can see the bright half of the moon to the west, and the moon phase at this time is called "winding". The first quarter moon can only be seen in the first half of the night, and it submerges into the west in the middle of the night.

After the winding, the moon becomes fuller day by day, and we can see most of the bright hemisphere of the moon, and the phase of the moon at this time is called "gibbous moon".

It's time for the lunar calendar. Ten.

At 5 or 16 o'clock, the moon runs on the celestial sphere to the opposite side of the sun, and the sun and the moon are 180 degrees apart, that is, the earth is located between the sun and the moon. At dusk, the full moon rises in the east.

and at dawn it sinks to the west.

After the full moon, the moon becomes "thin" as the sun and moon positions get closer. It goes through the gibbous moon, the last quarter and the crescent moon in turn, and finally, returns to the position of the new moon. In China, it is customary to call the "Moon" in the second half of the month "the waning moon".

The first and second quarters, the waxing crescent and waning moons are similar in appearance, but they appear at different times, in different positions, and in the direction of their bright surfaces. The 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 and last quarters appear separately.

In the eastern sky at dawn and in the second half of the night, their "faces" are facing east, i.e., the eastern half is bright. Since the date of the lunar calendar in China is arranged according to the phases of the moon, the working people of ancient China sometimes relied on it to judge the date of the lunar calendar and the approximate time of the night.

The average time it takes for the moon to move from the new moon position to the time it returns to the new moon position is days, that is, the average period of change in the phases of the moon is days, which is called a "synodic month".

The moon sometimes changes differently. Equivalently, sometimes fat, sometimes thin.

The reasons for the change of the moon are as follows:

The reason for the change in the phases of the moon is related to the nature of the moon itself and the relative position of the moon, the earth, and the sun. The moon itself does not emit light, and when illuminated by the sun's rays, half of the sphere facing the sun is a bright area, and the other half of the sphere is a dark area (blocked by itself). As the position of the Moon changes relative to the Earth and the Sun, the illuminated side of the Moon is sometimes facing the Earth and sometimes facing away from the Earth; Sometimes the part of the moon facing the earth is larger, sometimes it is smaller, so there are different phases of the moon.

Influence of the Moon on Earth:

The first aspect is lighting, the earth can rely on the moon to illuminate the night, some time ago my country launched an artificial moon to illuminate Chengdu, and there are some biological clocks, which are necessary.

The second aspect is the tides: the same gravitational pull that the Moon has on the Earth, which gives the Earth a slightly elliptical shape, and this deformation has little effect on the solid land, but causes tides along the coastline.

Tides, in turn, affect the speed of the Earth's rotation and the distance from the Moon, with two high and low tides per day on the surface of the Earth as it enters and exits the zone of expansion caused by the Moon's gravity. The actual height of the tides depends on the position of the Moon in its orbit and also on the local topography.

The third aspect is the gravitational force of the moon: Dr. Sheroux Pearson, a scientist at NASA, pointed out that when the solar system was first formed, the moon was pulled by the earth and became its satellite, and the moon had a great impact on the earth in the process of being pulled closer to the earth, and the moon had a tidal attraction effect on the earth.

The first day of the new month is the new moon and cannot be seen; After that, it becomes crescent-shaped a little bit, at first.

The crescent-shaped moon phase in March and April is called the crescent moon; The seventh and eighth of the first month are called the first quarter moon.

The cycle of the phases of the moon is the day, called a synodic month, which is the ** of the month and week in the calendar. This time is longer than the time it takes for the Moon to revolve (sidereal months) because when the Moon revolves around the Earth, the Earth also revolves around the Sun.

Since the moon itself does not emit light and is not transparent:

When illuminated by sunlight, the half of the sphere facing the sun is the light area, and the other half of the sphere is the dark area (blocked by itself). As the position of the Moon changes relative to the Earth and the Sun, the illuminated side of the Moon is sometimes facing the Earth and sometimes facing away from the Earth; Sometimes the shiny part facing the Earth is larger, sometimes it is smaller, so that different phases of the moon appear.

It can be simply summarized into two things:

1. The moon does not emit light and is opaque.

2. It is related to the relative position of the moon, earth and sun.

Around the 30th day of the lunar month or the first day of the lunar month, the Moon is located between the Sun and the Earth. People on Earth happen to see the moon turning away from the sun, so they can't see the moon on the earth, which is called the new moon or new moon, which is the first day of the lunar calendar. This phase of the moon rises and sets with the sun, and its presence is only noticeable during a solar eclipse.

Since the moon itself does not emit light, the half of the sphere facing the sun is a bright area, and the other half of the sphere is a dark area. As the position of the Moon changes relative to the Earth and the Sun, the illuminated side of the Moon is sometimes facing the Earth and sometimes facing away from the Earth; Sometimes the part of the moon facing the Earth is larger, sometimes it is smaller, so that different phases of the moon appear.

Whenever the moon orbits between the sun and the earth, and the hemisphere illuminated by the sun is facing away from the earth, people cannot see the moon on the earth, and this day is called the "new moon", also called the "new moon", which is the first day of the lunar calendar.

After the new moon, the moon follows the direction of the earth's rotation, and the bright area gradually turns to the earth, and the moon can be seen on the earth showing a trace of slender silver hooks, appearing in the western sky, bowing its back towards the sunset, this moon phase is called "moth eyebrow moon", which is the beginning of the lunar calendar.

Three, four. Subsequently, the moon moves away from the sun in the sky day by day, at the beginning of the lunar calendar.

On July and August, half of the bright area facing the Earth, one can see the half moon (convex facing west), and this phase of the moon is called the "first quarter moon".

When the Moon moves in the direction of the Earth's back sun, it is the tenth day of the lunar calendar.

Five, ten. On the sixth and seventeenth, the bright areas of the moon are all facing the earth, and we can see a full moon, and this phase of the moon is called the "full moon", also called "hope".

"Months" originate from the moon's cycle, and by looking at the sky, you can find changes and find patterns.

Like other celestial bodies, the Moon is in eternal motion. As the Moon moves a large distance from west to east in the starry sky every day, its shape is constantly changing, which is called the phase change of the Moon.

1) When the moon runs between the earth and the sun, and the hemisphere illuminated by the sun carries the earth on its back, we can't see the moon, which is called"New Moon", also called"Shuo", which is the first day of the lunar calendar.

2) After the crescent moon, the illuminated part of the moon gradually turns to the earth, and we see a hook crescent moon, called"Eyebrows", which is the beginning of the lunar calendar.

3. The fourth day of the first month. 3), the beginning.

On the seventh and eighth days of the first month, I see a half moon (convex edge to the west), which is called"First Quarter Moon"。

4) On the tenth day of the lunar calendar.

Five, ten. 6. 17, the bright side of the moon is all facing the earth, and we can see a full moon, called"Full Moon", also called"Look"。

5) After the full moon, the bright side of the moon gradually becomes smaller, and it reaches the twentieth day of the lunar calendar.

Twenty-three, and you can see the half moon (convex to the east), called"Last quarter moon"。The second quarter moon rises in the east in the middle of the night.

6) In another week, the moon returns"Shuo"。

This is how the phases of the moon change over and over again. If you calculate it by the cycle of the moon phase change, from the new moon to the next new moon, it is one"Synodic month", for days or so. The length of a month in the Chinese lunar calendar is based on"Synodic month"Positive.

During the lunar calendar, when the moon moves between the Earth and the sun, a solar eclipse is possible. Looking at the time the Earth is between the Moon and the Sun, it is possible to have a lunar eclipse.

Since the Moon orbits the Earth once a month, the angle between the Earth, the Moon, and the Sun is constantly changing; We call it a synodic month. The appearance of a continuous crescent moon takes days (709 hours) and varies as the lunar orbital period (measured by stars) varies as the Earth simultaneously revolves around the Sun.

You should know the rules!

The change of the moon is the new moon - the crescent moon -First Quarter Moon- Wax and convex - full moon - Lost convex - last quarter moon - waning moon - new moon

On the first day of the lunar calendar, the moon.

Running between the Earth and the Sun, the illuminated hemisphere carries the Earth on its back, and we can't see the Moon, called"New Moon", also called"Shuo"。

After the new moon, the illuminated part gradually turns to the earth, at the beginning of the lunar calendar.

Three, four, we can see a hook crescent moon, called"Eyebrows"；Beginning.

Seven, eight, see the half moon (convex edge to the west), called"First Quarter Moon"；On the fifteenth or sixteenth day of the lunar calendar, the bright side is all facing the earth, and then we see the round moon, called"Full Moon", also called"Look"。

From then on, the bright part of the moon was lost day by day, and it was time for the lunar calendar.

Two. Ten. 2. 23 And I saw a half moon (convex to the east), which was called"Last quarter moon"；Another week, back again"Shuo"。Moon phases.

And so it keeps changing. From "Shuo" to "Shuo" or from "Wang" to "Wang", the average period experienced is 12:44 minutes and seconds on the 29th, which is called one"Synodic month"。

Identification method

Assuming that the Full Moon is a circle, then no matter how the moon phases change, the line connecting its upper and lower vertices must be the diameter of the circle (lunar eclipse).

when the moon phase is irregular).

When we see the outer edge of the moon phase close to the shape of the reverse C, then the moon phase at this time is the moon phase before the 15th day of the lunar calendar, on the contrary, when we see the outer edge of the moon phase is close to the shape of the C letter, then the moon phase at this time is the moon phase after the 15th day of the lunar calendar.