Uranus hosts a diverse family of moons that vary dramatically in size, from small captured asteroids to substantial worlds with complex geology. Understanding uranus moons size helps reveal how this distant system formed and evolved.
Below is a focused overview of the major Uranian moons, their key dimensions, and how they compare across different categories.
| Moon | Diameter (km) | Discovery Year | Orbit Type |
|---|---|---|---|
| Titania | 1,578 | 1787 | Major, regular |
| Oberon | 1,523 | 1787 | Major, regular |
| Umbriel | 1,169 | 1851 | Major, regular |
| Ariel | 1,158 | 1851 | Major, regular |
| Miranda | 472 | 1948 | Major, regular |
| Portia | 142 | 1986 | Inner small, regular |
| Puck | 162 | 1985 | Inner small, regular |
| Mab | ~25 | 2003 | Inner small, regular |
Major Uranian Moons Dimensions
Titania and Oberon
Titania and Oberon are the two largest uranus moons size, each spanning over 1,500 kilometers in diameter. Their surfaces show a mixture of ancient craters and younger features, indicating geological activity long after their formation.
Umbriel and Ariel
Umbriel and Ariel are similar in scale, with diameters just beneath 1,200 kilometers. Differences in crater density and surface coloration suggest varied thermal histories and impact exposure despite their comparable uranus moons size.
Size Distribution Among Inner Moons
Small Regular Satellites
The inner moons such as Portia, Puck, and Mab are tiny compared to the major satellites, yet they play an outsized role in shaping Uranus's ring structure. Their modest uranus moons size makes them more susceptible to orbital perturbations and ring interactions.
Captured Asteroid Candidates
Extended Irregular Population
Beyond the regular moons, weaker evidence suggests a population of captured objects with far more eccentric and inclined paths. These bodies would be smaller on average and highlight the dynamic history of the uranus moons size landscape.
Physical Characteristics and Composition
Density and Internal Structure
Measurements of uranus moons size combined with mass estimates indicate that the larger moons are roughly half water ice by volume. This structural makeup influences how impacts deform craters and how the moons respond to tidal forces.
Key Takeaways on Uranus Moons Size
- The major moons Titania and Oberon are the biggest, each over 1,500 km across.
- Umbriel and Ariel are slightly smaller but still substantial at about 1,150–1,170 km in diameter.
- Miranda, while smaller at 472 km, has a varied surface shaped by past tectonics and impacts.
- Inner small moons like Portia and Puck are under 150 km across and strongly influence the rings.
- Many faint irregular satellites are likely captured bodies, extending the size range even farther.
- Density and composition data suggest that water ice dominates the larger moons’ interiors.
FAQ
Reader questions
What is the largest moon of Uranus?
Titania is the largest moon of Uranus, with a diameter of about 1,578 kilometers.
How does the size of Miranda compare to other Uranian moons?
Miranda is substantially smaller than the major moons, with a diameter of roughly 472 kilometers, yet it displays the most varied terrain per unit area.
What is the smallest moon of Uranus with a verified orbit?
Among confirmed moons, Mab is one of the smallest, with an approximate diameter of 25 kilometers.
Do Uranus's moons increase in size with distance from the planet?
No clear trend links uranus moons size to orbital distance, since the largest satellites occupy both middle and outer regions while many small moons are found closer in.