Tithonium and Ius Chasma are the northern and southern trenches in the western troughs of the giant Valles Marineris canyon system, the largest canyon system in our solar system.

Tithonium Chasma measures about 805 km east-west and Ius Chasma 840 km while Valles Marineris stretches for roughly 3800 km starting in the west with Noctis Labyrinthus and ending with Capri and Eos Chasma in the east. The distance this large canyon system spans equals the distance almost all the way across the United States (or from the North Cape to the southern tip of Sicily). The term chasma was designated by the International Astronomical Union to refer to a steep- sided elongate depression. Within the image presented here, the largest height differences from the plateau down into the deepest regions within the chasma reach more than 7000 m. The plan view color image shows Ius Chasma to the left (south) and Tithonium Chasma to the right (north). The plateau regions around and between the chasmata strikingly show the large fractures, that accompanied the formation of Valles Marineris.