Umbriel

noun Um·bri·el \ ˈəm-brē-ˌel \

Definition of Umbriel

astronomy
: the third largest satellite of Uranus with a diameter of approximately 730 miles (1170 km)
  • Earlier this year, Buratti and her co-workers reported other evidence suggesting that Umbriel might be a Uranian oddity. Analyzing photographs taken through various color filters by the Voyager 2 spacecraft, they found that the ratio of green light to violet light varies widely over Umbriel's surface.
  • Science News16 Nov. 1991

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First Known Use of umbriel

1874


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