Tithonium Chasma is a large canyon in the Coprates quadrangle of

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

at 4.6° south latitude and 84.7° west longitude. It is about 810 km long and was named after a classical albedo feature.

Valles Marineris Canyon System

Tithonium Chasma is a major part of the largest canyon system in the Solar System; this great canyon would go almost all the way across the United States. The name for the whole system of canyons is

Valles Marineris Valles Marineris (; Latin for ''Mariner program, Mariner Valleys'', named after the Mariner 9 Mars orbiter of 1971–72 which discovered it) is a system of canyons that runs along the Mars, Martian surface east of the Tharsis region. At more than ...

. Starting at the west with

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 faul ...

in the Phoenicis Lacus quadrangle, the canyon system ends in the

Margaritifer Sinus quadrangle The Margaritifer Sinus quadrangle is one of a series of list of quadrangles on Mars, 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Margaritifer Sinus quadrangle is also referred ...

with Capri Chasma and Eos Chasma (in the south). The word Chasma has been designated by the International Astronomical Union to refer to an elongate, steep-sided depression. Valles Marineris was discovered by and named for the

Mariner 9 Mariner 9 (Mariner Mars '71 / Mariner-I) was a robotic spacecraft that contributed greatly to the exploration of Mars and was part of the NASA Mariner program. Mariner 9 was launched toward Mars on May 30, 1971, from Spaceport Florida Launch Comp ...

mission. Moving east from Noctis Labyrinthus, the canyon splits into two troughs, Tithonium and Ius Chasma in the south. In the middle of the system are very wide valleys of Ophir Chasma (north),

Candor Chasma Candor Chasma is one of the largest canyons in the Valles Marineris canyon system on Mars. The feature is geographically divided into two halves: East and West Candor Chasmas, respectively. It is unclear how the canyon originally formed; one the ...

, and Melas Chasma (south) and farther to the east is Coprates Chasma. At the end of Coprates Chasma, the valley gets wider to form Capri Chasma in the north and Eos Chasma in the south. The walls of the canyons often contain many layers. The floors of some of the canyons contain large deposits of layered materials. Some researchers believe that the layers were formed when water once filled the canyons. The canyons are deep as well as long; in places, they are deep. In comparison, the Earth's

Grand Canyon The Grand Canyon is a steep-sided canyon carved by the Colorado River in Arizona, United States. The Grand Canyon is long, up to wide and attains a depth of over a mile (). The canyon and adjacent rim are contained within Grand Canyon Nati ...

is only deep.

Layers

Images of rocks in the canyon walls almost always show layers. Some layers appear tougher than others. In the image below of Ganges Chasma Layers, as seen by HiRISE, one can see that the upper, light-toned deposits are eroding much faster than the lower darker layers. Some cliffs on Mars show a few darker layers standing out and often breaking into large pieces; these are thought to be hard volcanic rock instead of soft ash deposits. Because of its closeness to the Tharsis volcanic region, the rock layers may be made of layer after layer of

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

flows, probably mixed with deposits of volcanic ash that fell out of the air following big eruptions. It is likely the rock strata in the walls preserve a long geological history of Mars. Dark layers may be due to dark lava flows. The dark volcanic rock

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

is common on Mars. However, light-toned deposits may have resulted from rivers, lakes, volcanic ash, or wind blown deposits of sand or dust. The Mars Rovers found light-toned rocks to contain sulfates. Probably having been formed in water, sulfate deposits are of great interest to scientists because they may contain traces of ancient life. MRO discovered sulfates, hydrated sulfates, and iron oxides in Tithonium Chasma with its CRISM instrument.Murchie, S. et al. 2009. A synthesis of Martian aqueous mineralogy after 1 Mars year of observations from the Mars Reconnaissance Orbiter. Journal of Geophysical Research: 114. Image:Coprates map.JPG, Map of Coprates quadrangle showing details of

, the largest canyon system in the Solar System. Some of the canyons may have once been filled with water. Image:Tithonium Chasma Layers.JPG, Tithonium Chasma Layers, as seen by

HiRISE High Resolution Imaging Science Experiment is a camera on board the '' Mars Reconnaissance Orbiter'' which has been orbiting and studying Mars since 2006. The 65 kg (143 lb), US$40 million instrument was built under the direction ...

Valles Marineris Canyon System

Layers

References

See also