The basic method of observing the moon phase

It only explains the observation of the moon phase in clear weather:

1. Every month, from the beginning of the lunar calendar, the moon is basically invisible on the first and second days of the first day, which is the first month. This is the moon, the earth and the sun are in a straight line. The moon and the sun rise in the east and set in the west at the same time.

2. On the fourth day of the third grade, the moon rises a little later than the sun, which can't be seen during the day. Only when the sun sets in the west, a linear moon appears in the west of the sky, which is a new moon, with a crescent gap to the east and an arc to the west.

3. From the fifth day to the sixth month, the teeth are getting fuller and fuller, and the position in the west is higher than that in the previous days. The position is already half a day in the west. The gap in the crescent moon is still eastward.

4. On the eighth day of the seventh day, the moon rises from the east at noon, but it can't be seen during the day. When the sun sets, the moon has already reached the center of the sky, which is half the moon, for the first quarter moon.

5. By analogy, at the fifteenth day of the lunar calendar, the moon "grows" into a full circle, which is a full moon. When the sun goes down, the moon rises in the east and then sets to the west.

6. After that, in the second half of the month, the moon will appear later every day. It was found that it was dark for a long time before the moon rose from the east, and a gap gradually appeared. The gap was westward, and the sun rose from the east before the moon set from the west.

7. And after the 22nd and 23rd lunar month, the moon rises in the east in the middle of the night, and the visible time is getting shorter and shorter.

8. In the first quarter or the second quarter, sometimes you can see the moon during the day. In the first quarter, you will see the moon in the east of the sun, and in the second quarter, you will see the moon in the west of the sun.

the law of moon phase change

1. On the first day of each month in the lunar calendar, the moon lies between the sun and the earth. People on the earth just see the moon deviating from the dark side of the sun, so they can't see the moon on the earth (equivalent to the "black moon"), which is called the new moon or new moon. This moon phase almost rises and sets with the sun, that is, it rises in the morning and sets at dusk, and its existence can only be detected during the solar eclipse.

2. After the new moon, the moon revolves around the earth to the east, so that the moon leaves the middle of the earth and the sun and leans to the side, that is, the moon is located to the east of the sun. The half moon illuminated by the sun faces west. On the earth, it can be seen that some of it is sickle-shaped and the convex surface faces the sun in the west, which is called the moth-eyebrow moon.

The moth rose after sunrise and set after sunset. She was in the sky with the sun and in the bright sky, so she couldn't see the moon phase. You can only see the moth-eyebrow moon in the western sky for a period of time after the sun sets.