The lunar eclipse is an astronomical phenomenon that occurs every time the Earth is between the Sun and the Moon, exactly in the line of intersection of its orbit to the Moon, the "line of nodes", and when the moon is in full phase or the new phase.
When this occurs, Moon enters in the area called the "umbra" (or shadow), or "penumbra" of the Earth and is fully or partially concealed for a few minutes.
To better understand: Imagine you took a ball and lit a lantern in her direction. The shadow that will form behind the ball will have a clearer part and another darker. The darkest part has the shape of a cone with the base of the ball and the lighter portion has the shape of a drum, also with the base (lowest) in the ball, round cone.
The cylinder, or the clearest region, is called the "penumbra" of partial shade space that gets a little light, and the darkest part, the cone is called the "umbra", part that receives no light, completely dark.
With any spherical body in the solar system is the same effect, and the lunar eclipse too.
It is as if the lantern were the sun, the ball was the Earth and the Moon was in the cone region, or "umbra". Why we can not see it during the eclipse.
It is as if the lantern were the sun, the ball was the Earth and the Moon was in the cone region, or "umbra". Why we can not see it during the eclipse.
It turns out that the moon, according to the inclination of its orbit, can pass only near the region "umbra", causing a partial eclipse, or even an eclipse "penumbral" when it only crosses the penumbra region. The latter can not be seen with the naked eye because the moon remains virtually the same brightness.
The main difference of the lunar eclipse and solar eclipse, which can be perceived by us, is that the lunar eclipse can be seen from anywhere in the earth's hemisphere that is facing the moon. Have a solar eclipse can only be seen the so-called " eclipse of the way ", that is the way that the" umbra "of the moon (the tip of the cone) travels through the earth's surface when the moon is between the Sun and the Earth.
Another difference is that the solar eclipses usually only last for about 7 minutes, while the lunar eclipse can last up to a little over 3 hours, while the total phase lasts about 1 hour.
EarthPlanet
Last Update:29/03/2015
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