The Moon is Earth’s only natural satellite. At about one-quarter the diameter of Earth, it is the largest natural satellite in the Solar System relative to the size of a major planet, the fifth largest satellite in the Solar System overall, and is larger than any known dwarf planet. Distance to Earth: 384,400 km Orbital period: 27 days Radius: 1,737.4 km Gravity: 1.62 m/s² Age: 4.53 billion years Surface area: 3.793×107 km2; (0.074 of Earth’s)