During a lunar eclipse
The moon is in its waning phase when less and less of the side facing the earth is lighted. This phase occurs after the full moon and leads up to the new moon when the side facing the earth is completely dark.
Waning
A waning moon
When the lighted part of the moon grows it is a "waxing moon".
The moon is always half lit as it revolves around the earth. When the moon is directly between the earth and the sun we can not see the side that is in sunlight because it faces away from us. As it continues to rotate around the earth we see more and more of the lighted side of the moon. When it finally gets to the point directly opposite the sun, we see the whole lighted moon, or the full moon. As it continues to rotate we see less and less of the lighted side until it is again directly between earth and the sun, and we see no moon at all: the new moon, or dark of the moon. It takes 14 days for the new moon to become a full moon, so it would take about 12 days for a crescent moon to become full.
The moon phase where you see less of the lighted side is called the New Moon. During this phase, the moon is positioned between the Earth and the Sun, causing the side of the moon that is illuminated by sunlight to face away from Earth. As a result, the moon appears mostly dark and is often not visible in the night sky.
When half of the lighted side of the moon's surface can be seen, the moon looks like a half circle filled in. Any less than that, and the moon appears crescent-shaped. I suspect that you're not describing what you're imagining.
No, during a full moon, we see the entire lighted side of the moon, whereas during a new moon, the lighted side of the moon is facing away from Earth so we see no lighted side at all.
It has no real effect on the moon at all. The only effect is that the rocks and dust lying on the lighted side of the moon become dark for a few hours.
a new moon is when the moon is forming again and a full moon is when the moon is fully formed <><><><><> The new moon is when the Moon is minimally lighted, while the full moon is when the Moon is maximally lighted.
This is what causes the so-called "phases" of the moon: although fully half of the moon is lighted, we can only see part of the lighted part. A person on earth hardly ever sees all of the lighted side of the moon. When he does, he calls the sight a "full moon."
"Waning" means that less and less of the moon's lighted side is visible from Earth as time goes on. That's what's happening during the entire two weeks from Full Moon until the next New Moon.