Phases of Moon

Phases of Moon

Phases of the Moon

Let us first understand some basic facts about the Moon.

** The Moon is the Earth’s only natural satellite at a distance of 238,855 miles from the Earth.

** Moon rotates around its own axis in exactly the same time it takes to orbit the Earth. It takes 27.3 days both to rotate on its axis and to orbit Earth.

** Its revolution and rotation is such that only one side of the moon always faces us. The other side is never visible to us.

** If you look at the sky, you will notice that the shape of the Moon changes each night. These different views are called the phases of the Moon.

So let’s learn about the phases of the Moon

The Moon goes through phases because: 1) the Moon is revolving around the Earth, 2) the Moon is reflecting sunlight towards the Earth

We see only that phase of the moon which reflects sunlight to us. Half of the Moon is always in sunlight and the other half of it is always dark. For this reason, we can see only the portion that is lit, depending on its position in the orbit.

The change from phase to phase is very gradual and takes about a month for the whole cycle.

There are eight recognized phases that the Moon goes through and they always occur in the same order.

Phase 1 - New Moon - The side of the moon that is facing the Earth is not lit up by the sun. At this time the moon is not visible to us because the  Moon is in between Earth and the Sun. (This is called Amavasya)

Phase 2 - Waxing Crescent –After two to three days we see a small part (less than 1/2) of the moon. The part that is lit up and is called Waxing Crescent.

Phase 3 - First Quarter –Within a week one half of the moon is lit up by the sunlight. At this point half of the Moon is visible.

Phase 4 - Waxing Gibbous - At this time more than half of the moon is lit up. The part that is lit is slowly getting bigger. Waxing means to slowly get bigger.

Phase 5 - Full Moon –On fifteenth day the side of the moon that is lit up by the sun is facing the Earth. The entire moon is lit up at this point because the Earth comes between Sun and the Moon. We call this phase as purnima.

Phase 6 - Waning Gibbous - The moon is not quite lit up all the way by sunlight. The part of the moon that is lit is slowly getting smaller. Waning means to slowly get smaller.

Phase 7 - Last Quarter - Half of the moon is lit up by the sun. The part that we can see lit up is slowly getting smaller.

Phase 8 - Waning Crescent - A small part of the moon is lit up at this point. It is getting smaller gradually.