An eclipse happens when one astronomical body obscures another astronomical object another. A lunar eclipse happens when the earth comes between the sun and the moon and the shadow thus formed by the earth is cast of the moon. A solar eclipse, on the other hand, occurs when the moon is between the sun and the earth and its shadow moves across the earth.

The earth’s shadow is long, conical shaped shadow, called the umbra, with an area of partial shadow called the penumbra extending outwards. A total lunar eclipse occurs when the moon is completely engulfed by the umbra. If it moves directly through the center, it is overshadowed for about two hours duration. A partial lunar eclipse occurs when only a part of the moon enters the umbra. Even during a total eclipse, the lunar disk is not completely dark; it is faintly illuminated with a red light refracted by the earth’s atmosphere.

Now let me explain solar eclipse. A total solar eclipse occurs when the moon’s umbra reaches the earth. Annular solar eclipse occurs if the moon passes between the earth and the sun but its shadow does not reach the earth. In areas outside the moon’s umbra but within the penumbra, a partial eclipse occurs. The duration of a total solar eclipse is about three minutes. The moon starts to cast a shadow around 1 hour before the total eclipse occurs. The sunlight when a total eclipse is slowly reduced to bright moonlight. This happens due to the corona. As the visible sun narrows to a thin crescent, the corona appears. At the moment before totality, brilliant points of light, called Baily’s beads, flash out. These points are caused by the sun shining through irregularities on the lunar surface.