what is the definition of PHASE of the moon and why does the moon seem to change?

Answer 1

The shape of the Moon changes as seen from Earth because while the same side of the Moon always faces the Earth, the half of the Moon that is lit is always changing. The phase of the Moon refers to what portion of it is lit as observed from Earth. When the side that faces the Earth is exactly the half that is lit, we see a full moon. When the lit side faces directly away, we have a new moon. If half of the side we can see is lit, we have a shape that we sometimes call a half moon, but the phase is technically called a "quarter moon" because it represents one fourth of the entire cycle. If most of the lit surface is facing away, but we can see just the very edge of it, that's a crescent moon.

Answer 2

As the moon circles the Earth, the shape of the moon appears to change; this is because different amounts of the illuminated part of the moon are facing us. The shape varies from a full moon (when the Earth is between the sun and the moon) to a new moon (when the moon is between the sun and the Earth).

Answer 3

The phases of the moon are simply the cahnges in the visibility of the moon during a lunar cycle. The changes are caused by the sahdow of the Earth blocking some of the sunlight that reflects off of the moon.

Answer 4

it's just the portion of the moon that's not getting sunshine as seen from earth