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 name "Tomb of Orcus". The Italian name ("Tomba dell'Orco") can also mean "Tomb of the Ogre", and it is used that way in Italy today. The second tomb has never been fully excavated. Though most of the walls are muraled, the artists did not complete the ceiling. A scientific analysis in 2001 revealed that the paint used contained cinnabar, ochre, orpiment, calcite, copper, and Egyptian blue. While the artwork in Orcus I is highly praised (particularly the painting of Velia Velcha; see below), some of the artwork of Orcus II is considered poorly done. It is likely that the French