Viking 1 Orbiter color mosaic of the eastern Tharsis region on Mars. At left, from top to bottom, are the three 25 km high volcanic shields, Ascraeus Mons, Pavonis Mons, and Arsia Mons. The shield at upper right is Tharsis Tholus. The canyon system at lower right is Noctis Labyrinthus, the westernmost extension of Valles Marineris. The smooth area at bottom center is Syria Planum. The distance between the calderas of Ascraeus and Pavonis Mons is 800 km. North is up. The images used to produce this mosaic were taken during orbit 1334 on 22 February 1980. (Viking 1 Orbiter MG01N104-334S0)