Valles Marineris is a system of canyons that runs along the Martian surface east of the Tharsis region. At more than 4,000 km (2,500 mi) long, 200 km (120 mi) wide and up to 7 km (23,000 ft) deep, Valles Marineris is the largest canyon of the Solar System.
Noctis Labyrinthus is a region of Mars located in the Phoenicis Lacus quadrangle, between Valles Marineris and the Tharsis upland. The region is notable for its maze-like system of deep, steep-walled valleys. The valleys and canyons of this region formed by faulting and many show classic features of grabens, with the upland plain surface preserved on the valley floor. In some places the valley floors are rougher, disturbed by landslides, and there are places where the land appears to have sunk down into pit-like formations. It is thought that this faulting was triggered by volcanic activity in the Tharsis region. Research described in December 2009 found a variety of minerals, including clays, sulfates, and hydrated silicas, in some of the layers.
The Thermal Emission Imaging System (THEMIS) is a camera on board the 2001 Mars Odyssey orbiter. It images Mars in the visible and infrared parts of the electromagnetic spectrum in order to determine the thermal properties of the surface and to refine the distribution of minerals on the surface of Mars as determined by the Thermal Emission Spectrometer (TES). Additionally, it helps scientists to understand how the mineralogy of Mars relates to its landforms, and it can be used to search for thermal hotspots in the Martian subsurface.
Arabia Terra is a large upland region in the north of Mars that lies mostly in the Arabia quadrangle, but a small part is in the Mare Acidalium quadrangle. It is densely cratered and heavily eroded. This battered topography indicates great age, and Arabia Terra is presumed to be one of the oldest terrains on the planet. It covers as much as 4,500 km (2,800 mi) at its longest extent, centered roughly at 21°N6°E with its eastern and southern regions rising 4 km (13,000 ft) above the north-west. Alongside its many craters, canyons wind through the Arabia Terra, many emptying into the large northern lowlands of the planet, which borders Arabia Terra to the north.
In planetary nomenclature, a chasma is a deep, elongated, steep-sided depression. As of 2020, the IAU has named 122 such features in the Solar System, on Venus (63), Mars (25), Saturn's satellites Mimas (6), Tethys (2), Dione (8) and Rhea (5), Uranus's satellites Ariel (7), Titania (2) and Oberon (1) and Pluto's satellite Charon (3). An example is Eos Chasma on Mars.
Juventae Chasma is an enormous box canyon on Mars which opens to the north and forms the outflow channel Maja Valles. Juventae Chasma is located north of Valles Marineris in the Coprates quadrangle and cuts more than 5 km into the plains of Lunae Planum.
Melas Chasma is a canyon on Mars, the widest segment of the Valles Marineris canyon system, located east of Ius Chasma at 9.8°S, 283.6°E in Coprates quadrangle. It cuts through layered deposits that are thought to be sediments from an old lake that resulted from runoff of the valley networks to the west. Other theories include windblown sediment deposits and volcanic ash. Support for abundant, past water in Melas Chasma is the discovery by MRO of hydrated sulfates. In addition, sulfate and iron oxides were found by the same satellite. Although not chosen as one of the finalists, it was one of eight potential landing sites for the Mars 2020 rover, a mission with a focus on astrobiology.
Echus Chasma is a chasma in the Lunae Planum high plateau north of the Valles Marineris canyon system of Mars. It is in the Coprates quadrangle. Clay has been found within it, meaning that water once sat there for a time. It may have been one of the many lakes that have been advanced for the Martian past.
The Oxia Palus quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Oxia Palus quadrangle is also referred to as MC-11.
The Coprates quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Coprates quadrangle is also referred to as MC-18. The Coprates quadrangle contains parts of many of the old classical regions of Mars: Sinai Planum, Solis Planum, Thaumasia Planum, Lunae Planum, Noachis Terra, and Xanthe Terra.
Eos Chaos is a rough, collapsed area in the Coprates quadrangle on Mars at 16.8° south latitude and 46.9° west longitude. It is about 490 km long and was named after the Greek name of Aurora, an albedo feature.
Capri Mensa is a mesa in the Coprates quadrangle of Mars at 14° south latitude and 47.4° west longitude. It is about 275 km long and was named after a classical albedo feature name.
Ophir Chasma is a canyon in the Coprates quadrangle of Mars at 4° south latitude and 72.5° west longitude. It is about 317 km long and was named after Ophir, a land mentioned in the Bible. In the Bible it was the land which King Solomon sent an expedition that returned with gold. It is a classical albedo feature name.
Ius Chasma is a large canyon in the Coprates quadrangle of Mars at 7° south latitude and 85.8° west longitude. It is about 938 km long and was named after a classical albedo feature name.
Tithonium Chasma is a large canyon in the Coprates quadrangle of Mars at 4.6° south latitude and 84.7° west longitude. It is about 810 km long and was named after a classical albedo feature.
Aureum Chaos is a rough, collapsed region in the Margaritifer Sinus quadrangle (MC-19) portion of the planet Mars at approximately 4.4° south latitude and 27° west longitude, it is also in the west of Margaritifer Terra. It is 368 km across and was named after a classical albedo feature name.
Coprates Chasma is a huge canyon in the Coprates quadrangle of Mars, located at 13.4° south latitude and 61.4° west longitude, part of the Valles Marineris canyon system. It is 966 km (600 mi) long and was named after a classical albedo feature name. It was named from the classical Greek name for the Dez River in Persia.
Ganges Mensa is a mesa and an interior layered deposit in Ganges Chasma, one of the peripheral valleys of Valles Marineris on Mars. The mesa rises up to 4 kilometres (13,000 ft) from the floor of Ganges Chasma, nearly to the same elevation as the surrounding plateaux of Lunae Planum. Like Hebes Mensa, the mesa is completely separated from the surrounding canyon walls and has sustained significant erosion that has caused it to retreat in areal extent.
Chaos terrain on Mars is distinctive; nothing on Earth compares to it. Chaos terrain generally consists of irregular groups of large blocks, some tens of kilometers across and a hundred or more meters high. The tilted and flat topped blocks form depressions hundreds of metres deep. A chaotic region can be recognized by a rat's nest of mesas, buttes, and hills, chopped through with valleys which in places look almost patterned. Some parts of this chaotic area have not collapsed completely—they are still formed into large mesas, so they may still contain water ice. Chaos regions formed long ago. By counting craters and by studying the valleys' relations with other geological features, scientists have concluded the channels formed 2.0 to 3.8 billion years ago.
Hebes Mensa is a large mensa that rises from the floor of Hebes Chasma, one of the chasmata of the Valles Marineris network on Mars. Some researchers have identified this mesa to be an interior layered deposit (ILD), similar to Ganges Mensa, and are named for alternating light-toned and dark-toned layers forming a stair-stepped stratigraphy. The faces of Hebes Mensa are sometimes fluted. It is 7.5 kilometres (4.7 mi) tall and 120 by 43 kilometres wide.
