what causes a super moon

A supermoon occurs when a full moon coincides with the Moon being at or near its closest approach to Earth in its elliptical orbit, a point known as perigee. Because the Moon's orbit around Earth is not a perfect circle but elliptical, the distance between the Moon and Earth varies. When the full moon happens near this closest point, the Moon appears larger and brighter than usual in the sky. This alignment happens only a few times a year due to the changing orientation of the Moon's orbit relative to Earth and the Sun.