Question

when we can see only a part of the Moon the eclipse is said to be a eclipses

Answer 1

Lunar Eclipse. It is said lunar Eclipse

Answer 2

Heya friend
Here is the answer

A lunar eclipse occurs when the Moon passes directly behind the Earth into its umbra (shadow). This can occur only when the sun, Earth, and moon are aligned (in "syzygy") exactly, or very closely so, with the Earth in the middle. Hence, a lunar eclipse can occur only the night of a full moon.

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