Our closest neighbor is the moon
The moon is a natural satellite of the Earth. The planet’s closest satellite to the Sun, since the planets closest to the Sun, Mercury and Venus, have no satellites.
The second brightest object in the sky after the Sun and the fifth largest natural satellite of the planet of the solar system.
The average distance between the centers of the Earth and the Moon is 384,467 km (0.002 57 AU, ~ 30 Earth diameters). The apparent stellar magnitude of the full moon in the earth's sky is 12.71m.
The illumination created by the full moon near the surface of the earth in clear weather is 0.25 - 1 lux.
The moon is the only astronomical object outside the earth that man has visited.