When a total lunar eclipse occurs, the positions of the sun, the earth and the moon will be in the same straight line in turn. When the moon moves to the shadow part of the earth, the area between the moon and the earth will see that the moon is missing because the sunlight is blocked by the earth. At this time, the sun, the earth and the moon are in the same straight line. Lunar eclipses can be divided into partial eclipses, total eclipses and penumbra eclipses. Lunar eclipses can only occur around the 15th day of the lunar calendar.
Total lunar eclipse, an astronomical term, is a kind of lunar eclipse. When the moon, the earth and the sun are completely in a straight line, the earth is in the middle, the whole moon enters the shadow of the earth, and the surface of the moon turns dark red to form a total lunar eclipse. The earth will have a shadow in the direction away from the sun, which is called earth shadow. The earth shadow is divided into umbra and penumbra. The umbra is a place that is not directly exposed to the sun, while the penumbra is only partially exposed to the sun.
The moon sometimes enters the earth shadow during its orbit around the earth, which leads to the phenomenon of lunar eclipse. When the whole moon enters the umbra, a total lunar eclipse will occur; However, if only part of them enter the umbra, only a partial lunar eclipse will occur. Total and partial eclipses are umbra eclipses.