Proteus . Neptune VIII - 1989N1 . Proteus [PROH-tee-us], like all six of Neptune's newly discovered small satellites, is one of the darkest objects in the solar system -- "as dark as soot" is not too strong of a description. ... Topographic Map of Proteus . ... As with all maps, it is the cartographer's interpretation; not all features are necessarily certain given the limited data available. ... This image is a shaded relief map of Proteus, a small inner satellite of Neptune. ...