Umbriel (moon) that obliterated its older surface. Covered by numerous impact craters reaching in diameter, Umbriel is the second most heavily cratered satellite of Uranus after Oberon. The most prominent surface feature is a ring of bright material on the floor of Wunda crater. This moon, like all moons of Uranus, probably formed from an accretion disk that surrounded the planet just after its formation. The Uranian system has been studied up close only once, by the spacecraft "Voyager 2" in January 1986. It took several images of Umbriel, which allowed mapping of about 40% of the moon’s surface. Umbriel, along with
Oberon (operating system) has minimal hardware requirements (133 MHz Pentium, 100MB hard disk, and a VESA 2 graphics card with a resolution of at least 1024x768 pixel, optionally a 3COM Network card). The basic system runs from a single HD-Floppy and additional software can be installed through the network. The full installation includes the Gadgets GUI. It is written completely in the Oberon programming language. Some confusion is caused by the fact that there exists a version called LNO (an acronym for Linux Native Oberon), which uses Linux as hardware abstraction layer (HAL). Its goal was to be as compatible as possible to