Tempe Terra is a heavily cratered highland region in the northern hemisphere of the

planet A planet is a large, Hydrostatic equilibrium, rounded Astronomical object, astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets b ...

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 ...

. Located at the northeastern edge of the

Tharsis Tharsis () is a vast volcanic plateau centered near the equator in the western hemisphere of Mars. The region is home to the largest volcanoes in the Solar System, including the three enormous shield volcanoes Arsia Mons, Pavonis Mons, and A ...

volcanic province, Tempe Terra is notable for its high degree of crustal fracturing and deformation. The region also contains many small

shield volcano A shield volcano is a type of volcano named for its low profile, resembling a shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more viscous lava ...

es,

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, and other volcanic structures. The region is named after the

albedo feature In planetary geology, an albedo feature is a large area on the surface of a planet (or other Solar System body) which shows a contrast in brightness or darkness (albedo) with adjacent areas. Historically, albedo features were the first (and usu ...

''Tempe,'' first used by astronomer E.M. Antoniadi in 1930 to describe a bright patch of terrain centered near 40°N, 70°W. The name comes from the

Vale of Tempe The Vale of Tempe or Tembi (; ; ) is a gorge in the Tempi municipality of northern Thessaly, Greece, located between Olympus to the north and Ossa to the south, and between the regions of Thessaly and Macedonia. The gorge was known to the Byz ...

, a valley located south of

Mount Olympus Mount Olympus (, , ) is an extensive massif near the Thermaic Gulf of the Aegean Sea, located on the border between Thessaly and Macedonia (Greece), Macedonia, between the regional units of Larissa (regional unit), Larissa and Pieria (regional ...

and celebrated by the

ancient Greeks Ancient Greece () was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity (), that comprised a loose collection of culturally and linguistically re ...

for its beauty. The

International Astronomical Union The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...

(IAU) formally designated the region Tempe Terra in 1979. ''Terra'' (pl. terrae) is a Latin descriptor term used in planetary geology for continent-like highland regions (i.e., extensive land masses) on other planets.Gazetteer of Planetary Nomenclature. http://planetarynames.wr.usgs.gov .

Location and description

Tempe Terra is located in the eastern half of the Arcadia quadrangle (MC-03) and the western edge of the

Mare Acidalium quadrangle The Mare Acidalium 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 Quadrangle (geography), quadrangle is located in t ...

(MC-04) in Mars' western hemisphere. It is centered at and spans about 2,700 km at its broadest extent. The region extends from about 30° to 54°N and from 265° to 310°E, covering approximately 2.1 million km²,Neesemann, A.; van Gasselt, S; Hauber, E; Neukum, G. (2010) Insights to the Evolution of the Tempe Terra Region, Mars: Refinements of Geologic and Tectonic Units. 41st Lunar and Planetary Science Conference; LPI:Houston, TX, Abstract #2685. . or an area roughly equivalent to that of

Saudi Arabia Saudi Arabia, officially the Kingdom of Saudi Arabia (KSA), is a country in West Asia. Located in the centre of the Middle East, it covers the bulk of the Arabian Peninsula and has a land area of about , making it the List of Asian countries ...

. It is bordered to the east by Chryse and Acidalia Planitiae, to the north by the low-lying plains of Arcadia and Vastitas Borealis, and to the south by the huge

outflow channel Outflow channels are extremely long, wide swathes of scoured ground on Mars.Carr, M.H. (2006), ''The Surface of Mars''. Cambridge Planetary Science Series, Cambridge University Press. They extend many hundreds of kilometers in length and are typ ...

system of

Kasei Valles The Kasei Valles are a giant system of canyons in Mare Acidalium and Lunae Palus quadrangles on Mars, centered at 24.6° north latitude and 65.0° west longitude. They are long and were named for the word for "Mars" in Japanese. This is one ...

Geology

Tempe Terra occupies a transition zone between the old, heavily cratered highlands of the Martian south and the geologically younger, lowland terrain of the north. Tempe Terra contains the northernmost exposures of ancient highland crust on the planet. The region is transected by large numbers of linear to

curvilinear In geometry, curvilinear coordinates are a coordinate system for Euclidean space in which the coordinate lines may be curved. These coordinates may be derived from a set of Cartesian coordinates by using a transformation that is locally inv ...

normal fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

s and

graben In geology, a graben () is a depression (geology), depressed block of the Crust (geology), crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German language, German, meaning 'ditch' or 't ...

s with ages that span much of Mars' geologic history. Research on extension, or rifts in the crust, has suggested Tempa Terra may be the most highly strained geologic region on Mars with a lot of low

es. There is evidence of valleys in Tempe Terra, including stream meanders, as in the image below. ESP 045590 2170hanging.jpg, Hanging valley, as seen by HiRISE under HiWish program This may have been a waterfall at one time. Image:ESP_025336channels.jpg, Channels, as seen by HiRISE under HiWish program. Stream appears to have eroded through a hill. File:29054cutoff.jpg, Stream meander and cutoff, as seen by HiRISE under HiWish program.

Gullies

Martian gullies are small, incised networks of narrow channels and their associated downslope

sediment Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...

deposits, found on the planet of

. They are named for their resemblance to terrestrial gullies. First discovered on images from

Mars Global Surveyor ''Mars Global Surveyor'' (MGS) was an American Robotic spacecraft, robotic space probe developed by NASA's Jet Propulsion Laboratory. It launched November 1996 and collected data from 1997 to 2006. MGS was a global mapping mission that examined ...

, they occur on steep slopes, especially on the walls of craters. Usually, each gully has a

dendritic Dendrite derives from the Greek word "dendron" meaning ( "tree-like"), and may refer to: Biology *Dendrite, a branched projection of a neuron *Dendrite (non-neuronal), branching projections of certain skin cells and immune cells Physical *Dendri ...

''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.Malin, M., Edgett, K. 2000. Evidence for recent groundwater seepage and surface runoff on Mars. Science 288, 2330–2335. They are believed 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 which themselves considered to be quite young. On the basis of their form, aspects, positions, and location amongst and apparent interaction with features thought to be rich in water ice, many researchers believed that the processes carving the gullies involve liquid water. However, this remains a topic of active research. The pictures below show a variety of gullies and gully features. Image:ESP_025771variousgullies.jpg, A variety of gullies originating at different levels are visible in this HiRISE image that was taken under the

HiWish program HiWish is a program created by NASA so that anyone can suggest a place for the HiRISE camera on the Mars Reconnaissance Orbiter to photograph. It was started in January 2010. In the first few months of the program 3000 people signed up to use HiR ...

. Image:25771gullybenches.jpg, This enlargement of a small part of the previous image shows terraces along a gully channel. The terraces were created when a new channel cut through the old surface. This means that the gully was not in a single event. Water must have flowed more than once in this location. Image:ESP_028290_2285gullies.jpg, Gullies in a crater. Some seem to be young, others are well developed. Picture was taken by HiRISE under the HiWish program. ESP 044707 2285gullies.jpg, Gullies along mesa wall in North Tempe Terra, as seen by HiRISE under HiWish program 44707 2285apron.jpg, Close view of gully apron, as seen by HiRISE under HiWish program Note this is an enlargement of the previous image. 44707 2285alcove.jpg, Close view of gully alcove, as seen by HiRISE under HiWish program Note this is an enlargement of a previous image. ESP 044852 2285gullies1.jpg, Gullies on wall of mesa, as seen by HiRISE under HiWish program

Linear ridge networks

Linear ridge networks are found in various places on Mars in and around craters. These features have also been called "polygonal ridge networks," "boxwork ridges", and "reticulate ridges." Ridges often appear as mostly straight segments that intersect in a lattice-like manner. They are hundreds of meters long, tens of meters high, and several meters wide. It is thought that impacts created fractures in the surface, these fractures later acted as channels for fluids. Fluids cemented the structures. With the passage of time, surrounding material was eroded away, thereby leaving hard ridges behind. ESP 047054 2160ridges.jpg, Wide view of ridge network, as seen by HiRISE under HiWish program 47054 2160largeridges.jpg, Close view of ridge networks, as seen by HiRISE under HiWish program Arrow points to small, straight ridge. 47054 2160largeridgeschanging.jpg, Close view of small and large ridges, as seen by HiRISE under HiWish program 47054 2160smallridges.jpg, Close view of small and large ridges, as seen by HiRISE under HiWish program

Pits and troughs

Pits and troughs are common on Mars. Large troughs (long narrow depressions) are called fossae in the geographical language used for Mars. This term is derived from Latin; therefore fossa is singular and fossae are plural. Several mechanisms can form them. Fossae can form when the crust is stretched until it breaks. The stretching can be due to the large weight of a nearby volcano. Fossae/pit craters are common near volcanoes in the Tharsis and Elysium system of volcanoes.Skinner, J., L. Skinner, and J. Kargel. 2007. Re-assessment of Hydrovolcanism-based Resurfacing within the Galaxias Fossae Region of Mars. Lunar and Planetary Science XXXVIII (2007) Studies have found that on Mars a fault may be as deep as 5 km, that is the break in the rock goes down to 5 km. Moreover, the crack or fault sometimes widens or dilates. This widening causes a void to form with a relatively high volume. When surface material slides into the void, a pit crater or a pit crater chain forms. On Mars, individual pit craters can join to form chains or even to form troughs that are sometimes scalloped.Wyrick, D., D. Ferrill, D. Sims, and S. Colton. 2003. Distribution, Morphology and Structural Associations of Martian Pit Crater Chains. Lunar and Planetary Science XXXIV (2003) File:ESP 053754 2125lineofpits.jpg, Line of pits, as seen by HiRISE under HiWish program Fossae often seem to start with a line of pits. File:ESP 053886 2145bigpits.jpg, Pits in shallow trough, as seen by HiRISE under HiWish program File:ESP 053805 2140troughs.jpg, Troughs (Fossae), as seen by HiRISE under HiWish program

Other images from Tempe Terra

The pictures below are probably formed from ice. The Martian surface displays many differed types of holes, pits, depressions, and hollows that are believed to have been caused by large amounts of ice disappearing from the ground. When the ice leaves, the ground collapses. Because of the thin atmosphere on the planet, the ice sublimates—goes directly from a solid phase to a gas phase. Dry ice does that on the Earth.

Eskers An esker, eskar, eschar, or os, sometimes called an ''asar'', ''osar'', or ''serpent kame'', is a long, winding ridge of stratum, stratified sand and gravel, examples of which occur in glacier, glaciated and formerly glaciated regions of Euro ...

form when a stream runs under a glacier and deposits material that is left behind when the glacier disappears. File:Tempe Terra.jpg, Tempe Terra as seen in MOLA colorized image. Red areas show highest elevations; blue, lowest.

Acidalia Planitia Acidalia Planitia is a plain on Mars, between the Tharsis volcanic province and Arabia Terra to the north of Valles Marineris, centered at . Most of this region is found in the Mare Acidalium quadrangle, but a small part is in the Ismenius Lacus ...

is the blue area at extreme right. The immense outflow channels of

is in the lower right. File:ESP 028672 2235hollows.jpg, Hollows formed by erosion on floor of crater, as seen by HiRISE under HiWish program Image:23503esker.jpg, Esker, as seen by HiRISE under the HiWish program. ESP 043824 2180layers.jpg, Layers, as seen by HiRISE under HiWish program Location is Tempe Terra in Arcadia quadrangle. 43824 2160layers.jpg, Layers, as seen by HiRISE under HiWish program Location is Tempe Terra Note: this is an enlargement of the previous image.

References

External links

Martian Ice - Jim Secosky - 16th Annual International Mars Society Convention

HiRISE image of a hill in Tempe Terra
{{Portal bar, Solar System Terrae on Mars Arcadia quadrangle Mare Acidalium quadrangle