The name of Earth's natural satellite is the moon. In terms of size, the moon is not the biggest natural satellite in the solar system, but it is large and ranks fifth among the other moons. In fact, the moon is one of the largest satellites compared to its planet.
Unlike Earth, the moon has no atmosphere, and therefore, no weather. It appears bright in the night sky because it reflects light from the sun. The moon travels around the Earth about once every 28 days in a nearly circular orbit. Earth and the moon are tidally locked, meaning that the same side of the moon always faces the Earth. Several theories exist about how the moon formed. One theory is that the moon resulted from a Mars-like object striking the Earth, and the debris from that collision formed the moon.