In the coming few months you are likely to hear about a 'supermoon'. Here are some facts about it. A full moon happen when the sun, Earth and moon line up, and the earth in present in the middle. From earth's surface it looks fully illuminated.

This happens because it is opposite the sun in the sky. In the east the moon shows up just like the sun sets in the west. Around 12 hours later the moon sets in the west and the sun rises in the east.

The Earth constantly revolves around the sun and the moon constantly circles around the Earth, thus making full moon an instantaneous event that occurs when the moon is exactly opposite the sun. On Saturday, August 29, such an alignment is going to happen at 2:35 p. m. EDT.

Just a minute before a full moon the moon's phase is 'waxing gibbous', and After a minute of full moon it is 'waning gibbous'.

A full moon happens around 29.53 days after the last full moon and this estimation is considered roughly because the orbit of moon around the Earth is not an ideal circle. Instead it is elliptical in shape. Due to this the exact time of full moon differ a little bat from one month to another.

The most significant thing that happens as a result of the moon's elliptical orbit is that at times the moon comes nearer to the Earth, and sometimes goes away. When the satellite is nearest it is called 'perigee' and when farthest it is known as 'apogee'.