The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates the energy mainly as light, ultraviolet, and infrared radiation, and is the most important source of energy for life on Earth.
this is the center of the universe
The Moon is Earth's sole natural satellite
the Moon is Earth's only natural satellite. Its diameter is about one-quarter the diameter of the Earth (comparable to the width of Australia).The Moon is the fifth largest satellite in the Solar System. It is larger than any of the known dwarf planets and is the largest (and most massive) satellite relative to its parent planet.