90482 Orcus Etruscan equivalent of the Roman Pluto, and later became an alternate name for Pluto. The surface of Orcus is relatively bright with albedo reaching 23%, grey in color and water-rich. The ice is predominantly in crystalline form, which may be related to past cryovolcanic activity. Other compounds like methane or ammonia may also be present. The existence of a satellite allowed astronomers to determine the mass of the system, which is approximately equal to that of the Saturnian moon Tethys. The ratio of masses of Orcus and Vanth is uncertain, possibly anywhere from 1:33 to 1:12. The diameter of Orcus
Tomb of Orcus Tomb of Orcus The Tomb of Orcus (), sometimes called the Tomb of Murina (), is a 4th-century BC Etruscan hypogeum (burial chamber) in Tarquinia, Italy. Discovered in 1868, it displays Hellenistic influences in its remarkable murals, which include the portrait of Velia Velcha, an Etruscan noblewoman, and the only known pictorial representation of the demon Tuchulcha. In general, the murals are noted for their depiction of death, evil, and unhappiness. Because the tomb was built in two sections at two stages, it is sometimes referred to as the "Tombs of Orcus I" and "II"; it is believed to have