Moon eclipse, definition and study. A-Z index of Cognitio.

A lunar eclipse is a well-known optical phenomenon during which the shadow of the Earth obscures all or part of the Moon and occurs when the latter is “full” when Sun, Earth and it are located aligned in this order.

Sun, definition and study. A-Z index of Cognitio.


A total lunar eclipse occurs when the Moon passes completely through the shadow of the Earth. During the total eclipse the Moon does not cease to receive light; the sunlight that crosses the earth’s atmosphere is mainly diverted by refraction and reaches the satellite giving it a coloration that has been observed mutually in the same eclipse: it ranges from the dark red copper to orange-red passing through other shades among which the brown and the blue – dark green. On rare occasions, the light that reaches the moon is exactly the color of the blood, but there is no way to predict it in advance. But this makes it even more unusual this lunar eclipse is that it is the first of a series of four consecutive total lunar eclipses, tetrades. An event that can occur at a distance of a few years but also quite rare. The last one took place in 2003 and 2004, but it can only take up to 7 times in the same century. One characteristic of eclipses is their periodicity, that is, they’re repeating the same sequence after a period called Saros cycle and discovered by ancient Babylonian astronomers. 

Saros Cycle, definition and study. A-Z index of Cognitio.

Saros Cycle

In fact, depending on the relative positions of Earth and Moon, and given that their motions are almost regular, and starting from the fact that if an eclipse occurs, our satellite must be in New Moon or Full Moon, and therefore near one of the two intersections of the lunar orbit with the planet earth orbit, the moon knots, there are times called: Draconian Month, Sinodic Month, Anomalistic Month. So that all things are repeated in the same way, these three periods must be synchronized and contained in multiple cycles of days. 

Moon eclipse, definition and study. A-Z index of Cognitio.



To open the video  click on the image, good view from your Alessandro Brizzi.

Moon eclipse, definition and study. A-Z index of Cognitio.

Moon eclipse