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How are moons in the solar system different from one another?

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Illustration showing the eight planets of the solar system in order from the Sun-Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune-depicted to scale by size, with labeled diameters in miles and kilometers. The Sun is partially visible on the left for comparison. — Solar system The planets (in comparative size) in order of distance from the Sun.

Moons in the solar system are remarkably diverse, representing a wide range of environments and physical characteristics. They differ from one another in several key ways:1

Geological Activity: Moons vary from geologically dead bodies to highly active worlds. For example, Io is the most volcanically active body in the solar system due to tidal heating, while Enceladus features active plumes and a potential subsurface ocean. In contrast, Earth’s Moon has little internal activity and has been geologically quiet for a long time.2345
Atmospheres: While most moons lack significant atmospheres, some are exceptions. Titan possesses a dense, complex atmosphere, and Enceladus has a localized water-vapor atmosphere.3
Composition and Density: Moons range from rocky bodies, like Earth's Moon, to icy worlds rich in water ice and other volatiles, such as those orbiting Saturn.43
Orbital Dynamics: Moons exhibit varied orbital behaviors, including synchronous rotation, retrograde orbits like that of Triton, and complex interactions such as shepherd moons or chaotic rotation, as seen with Hyperion.12