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 (especially her eye) bears the influence of Hellenistic art. Unlike the Mona Lisa, however, she is noted for her grimace or sneer. The Tomb of Orcus II (sometimes distinguished as "the" Tomb of Orcus) was constructed around 325 BC. Its entrance is guarded by paintings of "Charun" (Charon), the keeper of the underworld, and a cyclops (possibly Polyphemus or Geryon). When the tomb was originally discovered, the cyclops was mistaken for the Roman god of the underworld, Orcus (hence the tomb's name). The back wall depicts a funeral procession overseen by "Aita" (Hades), the Etruscan god of the underworld, and