Information about solar and lunar eclipses, the causes of their formation.

A lunar eclipse is a special astronomical phenomenon in which when the Moon moves to the shadow of the Earth, the area between the Moon and the Earth will be blocked by the Earth due to the sun's rays, and a piece of the Moon is now missing.

A solar eclipse is between the sun, the moon and the earth in the same straight line, the moon blocks the sun's rays, so that some parts of the earth, even during the day, do not see the sun or only see the mutilated sun, the sun is completely obscured is called a total solar eclipse, and the partially covered is called a partial solar eclipse.

Lunar eclipses generally occur twice a year, with a maximum of 3 occurrences and sometimes none at all. Because in general, the Moon passes either above or below the Earth's umbra, rarely passing through or partially passing through the Earth's umbra, so a lunar eclipse generally does not occur.

According to observational data, the percentages of penumbral lunar eclipses, partial lunar eclipses, and total lunar eclipses in the middle of each century are about, and.

The earliest record of a lunar eclipse is that of Mesopotamia in 2283 BC. When China was in the Han Dynasty, Zhang Heng had already discovered the principle of lunar eclipses. Aristotle in the 4th century BC deduced that the earth was round based on the roundness of the earth's shadow seen by a lunar eclipse.

The ancient Greek astronomer Aristarchus in the 3rd century BC and Hipparchus in the 2nd century BC both proposed to measure the size of the sun, the earth, and the moon by lunar eclipses.

Iba Valley also proposed to measure geographic longitude by observing lunar eclipses at the same time in two places far apart. In the 2nd century, Ptolemy used ancient records of lunar eclipses to study the movement of the moon, a method that continues to this day.

1.Solar eclipse. and the principle of formation of lunar eclipses are due to the straight line propagation of light.

2.The specific reasons for the formation are as follows: a solar eclipse is between the sun, the moon and the earth in the same straight line, the moon blocks the sun's rays, so that some parts of the earth, even during the day, can not see the sun or see the mutilated sun, and the sun is completely obscured as a total solar eclipse.

The occlusion is called a partial solar eclipse.

3.A lunar eclipse is a lunar eclipse in which the earth blocks the sun's rays in the same straight line, causing the moon to become black in the clear night sky, and the lunar eclipse is also divided into a total lunar eclipse.

and a partial lunar eclipse.

A solar eclipse is when the moon circles the earth and turns between the sun and the earth, if the sun, the moon, and the earth are exactly lined up or close to a straight line, the moon blocks the sunlight that shoots to the earth, and the black shadow behind the moon falls on the earth, and the solar eclipse phenomenon occurs.

A lunar eclipse is caused by the Earth blocking sunlight between the Sun and the Moon, and when the Earth is between the Moon and the Sun, the Moon has no daylight (the Moon itself does not emit light). Solar and lunar eclipses are typical examples of light propagating in a straight line in celestial bodies.

A total solar eclipse occurs when the Moon blocks all the sun, a partial solar eclipse occurs when part of the sun is occluded, and an annular solar eclipse occurs when part of the sun is occluded. A total solar eclipse lasts no more than 7 minutes and 31 seconds. The maximum length of an annular solar eclipse is 12 minutes and 24 seconds.

In order to delay the observation of the total solar eclipse, an astronomer in France chased the shadow of the moon in a supersonic plane, extending the observation time to 74 minutes. China has the oldest record of solar eclipses in the world, and there have been definite records of solar eclipses more than 1,000 years BC.

The time of the solar eclipse is often on the first day of the lunar month, and the lunar eclipse is on the fifteenth day of the month.

As the saying goes, "I can't hide from the fifteenth day of junior high school". Because on the first day of each month, the position of the moon is exactly between the sun and the earth, and it rises and sets at the same time as the sun, which is called the new moon on the lunar calendar.

Due to the interrelationship between the revolution of the earth and the moon, sometimes the moon will become a line with the sun and the earth, and the area where the moon blocks the sunlight forms a solar eclipse, and the area where the sun cannot be seen at all is a total solar eclipse, and the area where the sun can be seen partially is a partial solar eclipse.

There is also a certain time when the moon can be seen blocking the middle part of the sun in a certain area, which is an annular solar eclipse. This is related to the perigee and apogee of the Moon's revolution and the position of the Earth's orbit.

The fifteenth day of the month is the lunar calendar, which should be the day of the full moon, when the sun sets, the moon rises, the sun, the earth, and the moon are also in a line, the earth is sandwiched between the sun and the moon, if the earth just blocks the sun's rays shining on the moon, the earth's shadow is cast on the moon, so there will be a lunar eclipse, of course, it will be divided into a total eclipse and a partial eclipse.

There are three types of lunar eclipses: partial lunar eclipses, total lunar eclipses, and penumbral lunar eclipses. When the Moon only partially enters the Earth's umbra, a partial lunar eclipse occurs in the potato cavity; And when the entire Moon enters the Earth's umbra, a total lunar eclipse occurs. As for the penumbral lunar eclipse, it means that the moon only passes over the penumbra of the earth, causing a very slight decrease in the brightness of the lunar surface, which is difficult to see with the naked eye, so it is not noticed.

1. On what day of the lunar calendar does a solar eclipse occur? Solar eclipses usually occur on New Year's Day, the first day of the lunar month.

2. Because when the moon is between the earth and the sun at this time, the moon will block the sun's light from the earth, and a solar eclipse will occur. However, because the Earth's orbit (ecliptic) and the moon's orbit (white path) are at an angle of 5°9, it is not the first day of the lunar calendar every month that a solar eclipse overshadows the plum. A solar eclipse is also known as a solar eclipse, and in folklore, this phenomenon is called a tengu eclipse.

3. Schematic diagram of solar eclipse and schematic diagram of lunar eclipse formation principle:

In a solar eclipse, it is the moon that blocks the sun.

In a lunar eclipse, it is the earth that blocks the moon.

The sun, the earth, and the moon are all in a straight line.

4. Solar eclipses and lunar eclipses have an observation range, and they cannot be seen anywhere on the earth.

5. When a solar eclipse occurs, if someone is in a suitable position on the moon, it will be possible to see a "geoscopic eclipse", and the earth will be partially blocked by the moon.

6. When a lunar eclipse occurs, if someone is in a suitable position on the moon, it is possible to see a "solar eclipse", where the sun is partially blocked by the earth.

7. In fact, both of these phenomena are formed by the principle of light propagating along a straight line. This is due to the direct relationship between the Earth and the Sun and the Moon. As one of the eight planets, the Earth moves around the Sun under the gravitational pull of the Sun, while the Moon is subject to the common gravitational pull of the Sun and the Earth, and the Moon revolves around the Earth.

So, the problem arises, when the sun, the earth, and the moon are in a straight line, there is a phenomenon that the sunlight is blocked.

The principle of solar (moon) eclipse is that the moon orbits the earth, and its orbital plane is called the white plane, and the moon orbits the sun with the earth at the same time, and this orbital plane is called the ecliptic plane.

The two planes are not aligned, but form an oblique intersection.

The Moon and the Earth itself are both celestial bodies that do not emit light, they shine in the sun.

Under the irradiation, a long shadow will be dragged out. When the Moon orbits between the Sun and the Earth, and the Sun, the Moon, and the Earth happen to be almost in the same straight line, the light rays from the Sun shining on the Earth are partially or completely obscured by the Moon, and people see a solar eclipse.

The principle of solar eclipse From this principle, we can know that the solar eclipse must occur on the new sun.

That is, the first day of the lunar calendar. However, not every new day will have a solar eclipse, because there is an angle of 5°09 between the ecliptic and white planes, and although the moon is located between the sun and the earth, the sun, moon and earth are not necessarily exactly in a straight line. A solar eclipse occurs only when the moon is moving near the intersection of the ecliptic and the white path.

Lunar eclipse. The principle of a lunar eclipse is the same, when the sun in motion of the moon and the outer side of the line connecting the earth, the shadow of the earth is projected on the moon, causing the moon to lose its brightness, that is, a lunar eclipse. Therefore, the lunar eclipse must occur around the 15th day of the lunar calendar.

There are generally three types of solar eclipses:

Total solar eclipse. Partial solar eclipse, annular solar eclipse.

As shown in the diagram, the Moon forms a cone-shaped shadow focal region on the side facing away from the Sun, which we call the shadow cone, the spire of the shadow cone is called the focal point, the area in front of the focal point of the shadow cone is called the umbra, the focal extension is called the pseudo-bumper shadow, and the area outside the shadow cone is called the penumbra.

Because the orbit of the earth around the sun and the moon around the earth is not exactly round, the distance between the sun, moon and earth is different at any time, so when the moon casts shadows, the earth will enter different shadow regions at different times, resulting in different solar eclipses.