Why do lunar eclipses occur? Why is there a lunar eclipse

Why is there a lunar eclipseAs follows:

1. The formation of a lunar eclipse From a physical point of view, the principle is that light propagates in a straight line in the same uniform medium, the sun, the earth, and the moon form a straight line positional relationship, and the moon enters the earth's umbra, which becomes the lunar eclipse we usually see.

2. The time of occurrence depends on how far the moon is from the earth, which determines how much of the earth's shadow can cover, and how long the moon travels in this shadow.

3. The process of total lunar eclipse is divided into five stages: initial loss, eclipse, eclipse, light, and recirclement. The degree to which the Moon is eclipsed is called "eclipse", which is equal to the ratio of the farthest distance between the edge of the lunar ring and the Earth's umbra at the time of the eclipse to the Moon's visual meridian.

4. When the Moon is in the umbra zone of the Earth, although the sun's rays cannot directly reach its surface and make it reflect, the Earth's atmosphere absorbs the blue, violet, yellow and other light with shorter wavelengths when receiving the sun's rays, and refracts the red light that receives less influence from atmospheric scattering to the Moon in the Earth's shadow, so that we can see the moon showing a round of red.

A lunar eclipse is a special astronomical phenomenon in which when the Moon moves to the shadow part of the Earth, the area between the Moon and the Earth will be obscured by the Earth's rays, and a piece of the Moon will be missing. The Sun, Earth, and Moon at this time happen to be (or almost) in the same straight line. Lunar eclipses can be divided into three types: partial lunar eclipses, total lunar eclipses, and penumbral lunar eclipses.

Lunar eclipses can only occur around the 15th day of the lunar calendar.

Studies have found that when the gravitational pull of the earth and the moon is at its strongest, it often causes people's emotional instability, and they are easily excited, quarrelsome, and fond of fighting. Seizures in mentally ill patients have increased significantly, and some people have caused insomnia, dreaminess, chest tightness, dizziness, and headaches.

The incidence of coronary heart disease and myocardial infarction has its own rules, and the death distribution curve of myocardial infarction is just similar to the curve of the gravitational force of the earth and the moon, so it has been pointed out that the blood flow of the myocardium can be affected when the gravitational force of the earth and the moon is at its maximum.

And on the day of the lunar eclipse, the incidence of dizziness, headache, chest tightness, insomnia, and dreaminess will increase significantly, and even increase the incidence to 49%.

For the diseased body that has lost the balance of self-control and regulation in the body, when the gravitational attraction of the earth and the moon increases, the self-control and regulation function in the body that has been out of balance is even more unbalanced. Therefore, the biological effects of cardiovascular patients on the day of the lunar eclipse are more intense, and there is a tendency to aggravate the seizures.

in the lunar calendar. Ten.

5. 16. The moon moves in the opposite direction to the sun. At this time, if the center of the Earth and the Moon are roughly in the same straight line, the Moon will enter the Earth's umbra and produce a total lunar eclipse. If only part of the Moon enters the Earth's umbra, a partial lunar eclipse occurs.

When the Moon enters the penumbra of the Earth, it should be a penumbral eclipse, but because its brightness is weakened very little and it is not easy to detect, it is not called a lunar eclipse, so there are only two kinds of lunar eclipses: total lunar eclipses and partial lunar eclipses. Lunar eclipses occur in the hope (full moon), but not every lunar eclipse occurs, which is the same as not every solar eclipse. A phenomenon in which the Moon is completely or partially obscured by the Earth's shadow.

Lunar eclipses generally occur on the sun, that is, on the fifteenth or sixteenth day of the summer calendar month, when the earth moves between the sun and the moon, but not every solar eclipse may occur, because there is an angle between the ecliptic and the white way, so only on the night of the moon, the moon and the lunar eclipse are continuous**, and the earth's shadow can be seen near the intersection of the ecliptic and the white path, and the observer on the earth can ** lunar eclipse.

The number of lunar eclipses that occur each year is generally 2. The diameter of the Sun is much larger than that of the Earth, and the Earth's shadow can be divided into umbra and penumbra. The diameter of the Earth is about 4 times that of the Moon, and in the orbit of the Moon, the diameter of the Earth's umbra is still twice that of the Moon.

A partial lunar eclipse occurs when the Moon is always partially obscured by the Earth's umbra.

And when the Moon enters the Earth's umbra in its entirety, a total lunar eclipse can be seen. If the Moon enters the penumbra region, the sun's light can also be obscured a little, this phenomenon is called a penumbral lunar eclipse in astronomical terms, but because the sunlight is still very strong in the penumbral region, in most cases the penumbral lunar eclipse is not easy to distinguish with the naked eye, but in fact penumbral lunar eclipses are a frequent occurrence.

A lunar eclipse is a special astronomical phenomenon in which when the Moon moves to the shadow part of the Earth, the area between the Moon and the Earth will be obscured by the Earth's rays, and a piece of the Moon will be missing. The Sun, Earth, and Moon at this time happen to be (or almost) in the same straight line. Lunar eclipses can be divided into three types: partial lunar eclipses, total lunar eclipses, and penumbral lunar eclipses.

Lunar eclipses can only occur around the 15th day of the lunar calendar.

A special astronomical phenomenon, the earth revolves around the sun, the moon revolves around the earth, when the earth runs between the moon and the sun, the sun's light is blocked, and the moon itself does not emit light, it reflects the sun's light and emits light, so without light, it is invisible.

A lunar eclipse occurs when the moon is blocked by the sun and does not shine on the earth.

Light travels in a straight line, and a lunar eclipse occurs when the Sun is between the Moon and the Earth.

When the Sun, Earth, and Moon are in the same straight line, and the Earth is between the Sun and the Moon, the Earth blocks the light from the Sun to the Moon, because there is no light, and the light cannot be reflected, so the Moon becomes dark.

The sun, the earth, and the moon are almost in the same straight line, so a lunar eclipse will be formed.