Links
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- Umbriel on Wikipedia
Umbriel
Details
Umbriel is the darkest of Uranus' large moons, an ancient cratered world that reflects only a small fraction of the sunlight that reaches it. Voyager 2 also revealed the bright Wunda ring on its dark surface, a feature whose origin remains uncertain.
Umbriel matters because it gives the Uranian moons their darkest, most ancient-looking face. It is one of the five major moons of Uranus, but unlike brighter Ariel or fractured Miranda, Umbriel reads as an old cratered surface where most of the drama is written in contrast rather than in fresh-looking terrain.
NASA describes Umbriel as the darkest of Uranus' largest moons, reflecting only about 16 percent of the light that strikes it. Voyager 2 images showed heavy cratering and a curious bright ring on the moon's dark surface. The ring, called Wunda, may be connected with frost deposits around an impact crater, but its exact origin remains uncertain.
That is why Umbriel belongs on this scale. It is close in size to Ariel and Charon, but its identity is not just a number. Umbriel shows how two icy moons in the same planetary system can land in very different visual and geological registers: one bright and comparatively fresh-looking, another dark, old, and still partly unexplained.
511km
Key facts
- Scale fact
- 1,170 kmdiameter
- Composition
- Water ice and silicate rock
Scale context
Where Umbriel sits on the full axis
Shared physical scale
1,165km
Together, these objects make the size change around Umbriel easy to compare at a glance.
Sources
References for Umbriel
Measurements and descriptive context are compiled by the Scale of Space team from the references below. If you find an error, please let us know.
- Umbriel — Wikipedia
- Visual reference: NASA Science (USGS / Tammy Becker / JPL-Caltech, Public domain)
Between the smallest and the largest, perspective is everything.
About
Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.
Guides turn parts of that scale into curated essays, while focused views let you explore the same range through specific groups of objects.