Moons

A natural satellite in astronomy is a smaller body which moves around a larger body. The smaller body is held in orbit by gravitation. The term is used for moons which go around planets, and it is also used for small galaxies which orbit larger galaxies.

Bodies which orbit planets are called moons. They vary in size. The Earth has only one moon. Some other planets have many moons, and some have none. When people write just "the moon", they are usually talking about the moon of the Earth. Earth's moon is written with a capital letter, Moon. The Latin word for the moon is luna, which is why the adjective used to talk about the moon is "lunar". For example, lunar eclipse.

Anything that goes around a planet is called a satellite. Moons are natural satellites. People also use rockets to send machines into orbit around the Earth. These machines are called artificial (man-made) satellites.

Planets in our Solar System that have moon(s):

• Earth, 1 moon
• Mars, 2 moons
• Jupiter, 67 moons
• Saturn, 62 moons
• Uranus, 27 moons
• Neptune, 14 moons

• Eris, 1 moon
• Pluto, 5 moons
• Haumea, 2 moons

Planets in our Solar System that do not have moons:

• Mercury
• Venus
• Makemake (dwarf planet)
• Ceres (dwarf planet)