Earth's Moon is the brightest and largest object in our night sky. The Moon makes Earth a more livable planet by moderating our home planet's wobble on its axis, leading to a relatively stable climate. It also causes tides, creating a rhythm that has guided humans for thousands of years.
The Moon was likely formed after a Mars-sized body collided with Earth several billion years ago.
Earth's only natural satellite is simply called "the Moon" because people didn't know other moons existed until Galileo Galilei discovered four moons orbiting Jupiter in 1610. In Latin, the Moon was called Luna, which is the main adjective for all things Moon-related: lunar.
Earth's Moon has inspired stories since the first humans looked up at the sky and saw its gray, cratered surface. Some observers saw among the craters the shape of a person's face, so stories refer to a mysterious "man in the Moon." Hungrier observers compared the craters to cheese and dreamed of an entire sphere made of delicious dairy products.
The Moon made its film debut in a 1902 black and white silent French film called "Le Voyage Dans la Lune" ("A Trip to the Moon"). And a year before astronauts walked on the Moon, "2001: A Space Odyssey" (1968) told the story of astronauts on an outpost on the Moon.
American astronauts have planted six American flags on the Moon. But that doesn't mean the United States has claimed it; in fact, an international law written in 1967 prevents any single nation from owning planets, stars, or any other natural objects in space.