Post contributed by Dr. Mike Sori, Lunar and Planetary Laboratory, University of Arizona
Uranus and its moons have only ever been visited by one spacecraft, Voyager 2, which flew by the system in 1986. One of its large moons, Umbriel, was found to have a mysterious bright ring 80-km-wide inside a 131-km-diameter crater named Wunda. Image 1 shows Umbriel and this annulus-shaped feature.
Image 1: Voyager 2 image 1334U2-001 showing the Uranian moon Umbriel; note the bright ring inside the crater Wunda at top of the image (which is at Umbriel’s equator).
