CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Uranus' largest moon Oberon

Uranus' outermost and largest moon, Oberon, is seen in this Voyager 2 image, obtained Jan. 22, 1986, from a distance of 2.77 million kilometers (1.72 million miles).

The clear-filter image, shuttered by Voyager's narrow-angle camera, shows that Oberon displays several distinct highly reflective (high-albedo) patches with low-albedo centers. Some of the bright patches are suggestive of radial patterns that could represent impact craters excavated from an icy surface.

On average, Oberon reflects about 20 percent of the incident sunlight. The moon is about 1,600 km (1,000 mi) in diameter; resolution of this image is 51 km (32 mi). It was taken two days before Voyager's closest approach to Oberon, at which point the spacecraft will be about 471,000 km (293,000 mi) away.

The Voyager Project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif.

Acquired: January 1986
  Uranus' largest moon Oberon
PIA 01352

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Alliance Member Comments
carolyn (CICLOPS) (Dec 29, 2008 at 9:37 AM):
Folks: You don't need to go to the photojournal for images of other outer solar system bodies. We have brought all the Voyager, Galileo and New Horizons images over to CICLOPS. This Oberon image can be found at:
kheider (Dec 29, 2008 at 2:18 AM):
More Oberon:
-- Kevin Heider
Mercury_3488 (Dec 28, 2008 at 5:41 PM):
Oberon is clearly denser & also the best Voyager 2 images of Oberon clearly show that Oberon has experienced cryovolcanism with dark flooding of crater floors & also Oberon shows evidence of lofty mountains, both of which Rhea lack.

Looks like more has happened with Oberon, geologically speking than Rhea, though we won't know much more till there is a return to the Uranian system.

Rhea does seem very dead considering it's quite large size, but Rhea's density does appear lower than both Titania's & Oberon's & both Titania & Oberon show evidence of having had activity, something sorely lacking with Rhea.

However Rhea does record the impact history of that part of the Saturn system very well.

Andrew Brown.
kheider (Dec 28, 2008 at 6:14 AM):
Oops. Titania might have something to say about which Uranian moon is both the largest and most massive. :-)

But it is interesting to compare Oberon (more massive) to Rhea (larger).
-- Kevin Heider