Holden is a 140 km wide crater situated within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars, located with the southern highlands. It is named after American astronomer Edward Singleton Holden. It is part of the Uzboi-Landon-Morava (ULM) system.
Terra Sirenum is a large region in the southern hemisphere of the planet Mars. It is centered at 39.7°S 150°W and covers 3900 km at its broadest extent. It covers latitudes 10 to 70 South and longitudes 110 to 180 W. Terra Sirenum is an upland area notable for massive cratering including the large Newton Crater. Terra Sirenum is in the Phaethontis quadrangle and the Memnonia quadrangle of Mars. A low area in Terra Sirenum is believed to have once held a lake that eventually drained through Ma'adim Vallis.
Tempe Terra is a heavily cratered highland region in the northern hemisphere of the planet Mars. Located at the northeastern edge of the Tharsis volcanic province, Tempe Terra is notable for its high degree of crustal fracturing and deformation. The region also contains a large number of small shield volcanoes, lava flows, and other volcanic structures.
Reull Vallis is a valley on Mars that appears to have been carved by water. It runs westward into Hellas Planitia. It is named after the Gaelic word for planet. It is found in the Hellas quadrangle.
Hypanis Valles is a 270 km valley in Xanthe Terra on Mars at 11° N, 314° E, in the Lunae Palus quadrangle. It appears to have been carved by long-lived flowing water, and a significant deposit exists at its outlet into the lowlands.
The Noachis quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Noachis quadrangle is also referred to as MC-27.
The Arcadia quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The quadrangle is located in the north-central portion of Mars’ western hemisphere and covers 240° to 300° east longitude and 30° to 65° north latitude. The quadrangle uses a Lambert conformal conic projection at a nominal scale of 1:5,000,000 (1:5M). The Arcadia quadrangle is also referred to as MC-3.
The Lunae 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 quadrangle is also referred to as MC-10. Lunae Planum and parts of Xanthe Terra and Chryse Planitia are found in the Lunae Palus quadrangle. The Lunae Palus quadrangle contains many ancient river valleys.
The Margaritifer Sinus quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Margaritifer Sinus quadrangle is also referred to as MC-19. The Margaritifer Sinus quadrangle covers the area from 0° to 45° west longitude and 0° to 30° south latitude on Mars. Margaritifer Sinus quadrangle contains Margaritifer Terra and parts of Xanthe Terra, Noachis Terra, Arabia Terra, and Meridiani Planum.
The Hellas quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Hellas quadrangle is also referred to as MC-28 . The Hellas quadrangle covers the area from 240° to 300° west longitude and 30° to 65° south latitude on the planet Mars. Within the Hellas quadrangle lies the classic features Hellas Planitia and Promethei Terra. Many interesting and mysterious features have been discovered in the Hellas quadrangle, including the giant river valleys Dao Vallis, Niger Vallis, Harmakhis, and Reull Vallis—all of which may have contributed water to a lake in the Hellas basin in the distant past. Many places in the Hellas quadrangle show signs of ice in the ground, especially places with glacier-like flow features.
The Eridania quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Eridania quadrangle is also referred to as MC-29.
The Phaethontis quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Phaethontis quadrangle is also referred to as MC-24.
The Thaumasia quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Thaumasia quadrangle is also referred to as MC-25 . The name comes from Thaumas, the god of the clouds and celestial apparitions.
The Argyre quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Argyre quadrangle is also referred to as MC-26. It contains Argyre Planitia and part of Noachis Terra.
Maja Valles is a large, ancient outflow channel in the Lunae Palus quadrangle on Mars. Its location is 12.6° north latitude and 58.3° west longitude. The name is a Nepali word for "Mars". Maja Valles begins at Juventae Chasma. Parts of the system have been partially buried by thin volcanic debris. Maja Valles ends at Chryse Planitia. This channel system begins at Juventae Chasma and eventually ends in Chryse Planitia.
Kasei Valles is a giant system of canyons in Mare Acidalium and Lunae Palus quadrangles on Mars, located at 24.6° north latitude and 65.0° west longitude. It is 1,580 km long and was named for the word for "Mars" in Japanese. Kasei Valles is one of the largest outflow channels on Mars.
Lobate debris aprons (LDAs) are geological features on Mars, first seen by the Viking Orbiters, consisting of piles of rock debris below cliffs. These features have a convex topography and a gentle slope from cliffs or escarpments, which suggest flow away from the steep source cliff. In addition, lobate debris aprons can show surface lineations as do rock glaciers on the Earth.
Sirenum Fossae is a long trough in several quadrangles including Memnonia quadrangle and Phaethontis quadrangle of Mars, centered at 35.57° south latitude and 197.26° west longitude. Sirenum Fossae is 2,735 km long and was named after a classical albedo feature name. Troughs on Mars like this one are called Fossae. Sirenum Fossae is believed to have formed by movement along a pair of faults causing a center section to drop down. This kind of feature is called a graben.
Fretted terrain is a type of surface feature common to certain areas of Mars and was discovered in Mariner 9 images. It lies between two different types of terrain. The surface of Mars can be divided into two parts: low, young, uncratered plains that cover most of the northern hemisphere, and high-standing, old, heavily cratered areas that cover the southern and a small part of the northern hemisphere. Between these two zones is a region called the Martian dichotomy and parts of it contain fretted terrain. This terrain contains a complicated mix of cliffs, mesas, buttes, and straight-walled and sinuous canyons. It contains smooth, flat lowlands along with steep cliffs. The scarps or cliffs are usually 1 to 2 km high. Channels in the area have wide, flat floors and steep walls. Fretted terrain shows up in northern Arabia, between latitudes 30°N and 50°N and longitudes 270°W and 360°W, and in Aeolis Mensae, between 10 N and 10 S latitude and 240 W and 210 W longitude. Two good examples of fretted terrain are Deuteronilus Mensae and Protonilus Mensae.
Martian gullies are small, incised networks of narrow channels and their associated downslope sediment deposits, found on the planet of Mars. They are named for their resemblance to terrestrial gullies. First discovered on images from Mars Global Surveyor, they occur on steep slopes, especially on the walls of craters. Usually, each gully has a dendritic alcove at its head, a fan-shaped apron at its base, and a single thread of incised channel linking the two, giving the whole gully an hourglass shape. They are estimated to be relatively young because they have few, if any craters. A subclass of gullies is also found cut into the faces of sand dunes, that are themselves considered to be quite young. Linear dune gullies are now considered recurrent seasonnal afeatures.
Gullies in the wall of Harmakhis, as seen by HiRISE.
