The moon is the closest spherical inline celestial body to the earth, which revolves round the earth. Due to this, it has been called the satellite of the earth. Its surface is rocky and uneven just like the earth’s surface. In comparison to earth, it is around 81 times smaller. It revolves on its axis in 29 days, and it revolves round the earth in 27 days. It shines due to the light obtained from the sun. Once in a month, its fully illuminated part comes in front of the earth.
In this part, we find its decreasing feature from Poornima to Amavasiya and increasing from Amavasiya to Poornima. These increasing feature and decreasing shapes of the moon are known as lunar phases and these are 16 in number. They have been depicted in the following diagram
