1,169 km
DIAMETER
4.14 DAYS
ORBITAL PERIOD
266,000 km
FROM URANUS
1851
DISCOVERED
4.14 DAYS
ROTATION PERIOD
#3
LARGEST URANUS MOON
THE DARK MOON
Umbriel is the third-largest moon of
Uranus and one of the darkest major
moons in the Solar System.
It was discovered in 1851 by William
Lassell, at the same time as Ariel.
Umbriel has a heavily cratered and
very ancient surface. The moon is
covered with impact craters and
large geological features.
One of its most recognizable features
is Wunda crater, a large impact crater
with a bright ring of material around
its floor.
Voyager 2 photographed Umbriel
during its 1986 flyby of Uranus.
The moon is composed mainly of
water ice mixed with rocky material.
UMBRIEL FEATURES
WUNDA CRATER
Wunda is a large impact crater
with a striking bright ring of
material near its interior.
DARK SURFACE
Umbriel has one of the darkest
surfaces among the major moons
of Uranus.
ANCIENT TERRAIN
Its heavily cratered landscape
suggests that much of its surface
has remained unchanged for billions
of years.
DID YOU KNOW?
Umbriel is one of the
darkest major moons of Uranus,
reflecting only a small fraction
of the sunlight that reaches it.
A DARK, ANCIENT SURFACE
Umbriel is the darkest of Uranus's five major moons and has a heavily cratered surface, suggesting that much of its exterior is geologically old. Compared with Ariel and Miranda, Voyager 2 saw fewer obvious signs of extensive recent resurfacing.
Its dark material and impact record provide a useful comparison with the brighter, more tectonically modified moons in the same system.
IMAGE:
NASA / JPL / VOYAGER 2
IMAGE SOURCE: WIKIMEDIA COMMONS
IMAGE SOURCE: WIKIMEDIA COMMONS