Why does the moon's size seem to fluctuate?

1 Answer

Moon orbits Earth in an elliptical orbit.

Explanation:

So the distance varies from 362600 Km to 405400 KM. .So when it is near to us we see it a little bigger,
During Moon set and Moon rise moon looks larger than normal
But it is optical illusion,If we measure angular diameter size will be same during moon set and moon at zenith..