Oberon (moon) up to 40 km and its temperature is around 180 K. However, the internal structure of Oberon depends heavily on its thermal history, which is poorly known at present. Oberon is the second-darkest large moon of Uranus after Umbriel. Its surface shows a strong opposition surge: its reflectivity decreases from 31% at a phase angle of 0° (geometrical albedo) to 22% at an angle of about 1°. Oberon has a low Bond albedo of about 14%. Its surface is generally red in color, except for fresh impact deposits, which are neutral or slightly blue. Oberon is, in fact, the reddest
Water on terrestrial planets of the Solar System Water on terrestrial planets of the Solar System The origin and development of water on terrestrial planets, Venus, Earth, Mars, and the closely related Earth's Moon, varies with each planetary body, with the exact origins remaining unclear. Additionally, the terrestrial dwarf planet, Ceres is known to have water ice on its surface. A significant amount of surface hydrogen has been observed globally by the Mars Odyssey GRS. Stoichiometrically estimated water mass fractions indicate that—when free of carbon dioxide—the near surface at the poles consists almost entirely of water covered by a thin veneer of fine material. This is reinforced by