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
Oberon (operating system) together with the editor called Write yielded V2. As foreshadowed in the table in section history above there was a major fork in the beginning of 1990s: V4 vs. System 3: The group around Jürg Gutknecht introduced persistent objects and object-libraries thereby extending the kernel. The group around realized similar features by introducing active elements mapped to a special character thereby extending fonts without changing the kernel. System 3 was sometimes also called Spirit of Oberon and later renamed to ETH Oberon, whereas V4 was sometimes also called Linz Oberon. A version of the Oberon System 3, which was integrated