1.
Planet
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The term planet is ancient, with ties to history, astrology, science, mythology, and religion. Several planets in the Solar System can be seen with the naked eye and these were regarded by many early cultures as divine, or as emissaries of deities. As scientific knowledge advanced, human perception of the planets changed, in 2006, the International Astronomical Union officially adopted a resolution defining planets within the Solar System. This definition is controversial because it excludes many objects of mass based on where or what they orbit. The planets were thought by Ptolemy to orbit Earth in deferent, at about the same time, by careful analysis of pre-telescopic observation data collected by Tycho Brahe, Johannes Kepler found the planets orbits were not circular but elliptical. As observational tools improved, astronomers saw that, like Earth, the planets rotated around tilted axes, and some shared such features as ice caps and seasons. Since the dawn of the Space Age, close observation by space probes has found that Earth and the planets share characteristics such as volcanism, hurricanes, tectonics. Planets are generally divided into two types, large low-density giant planets, and smaller rocky terrestrials. Under IAU definitions, there are eight planets in the Solar System, in order of increasing distance from the Sun, they are the four terrestrials, Mercury, Venus, Earth, and Mars, then the four giant planets, Jupiter, Saturn, Uranus, and Neptune. Six of the planets are orbited by one or more natural satellites, several thousands of planets around other stars have been discovered in the Milky Way. e. in the habitable zone. On December 20,2011, the Kepler Space Telescope team reported the discovery of the first Earth-sized extrasolar planets, Kepler-20e and Kepler-20f, orbiting a Sun-like star, Kepler-20. A2012 study, analyzing gravitational microlensing data, estimates an average of at least 1.6 bound planets for every star in the Milky Way, around one in five Sun-like stars is thought to have an Earth-sized planet in its habitable zone. The idea of planets has evolved over its history, from the lights of antiquity to the earthly objects of the scientific age. The concept has expanded to include not only in the Solar System. The ambiguities inherent in defining planets have led to much scientific controversy, the five classical planets, being visible to the naked eye, have been known since ancient times and have had a significant impact on mythology, religious cosmology, and ancient astronomy. In ancient times, astronomers noted how certain lights moved across the sky, as opposed to the fixed stars, ancient Greeks called these lights πλάνητες ἀστέρες or simply πλανῆται, from which todays word planet was derived. In ancient Greece, China, Babylon, and indeed all pre-modern civilizations, it was almost universally believed that Earth was the center of the Universe and that all the planets circled Earth. The first civilization known to have a theory of the planets were the Babylonians
2.
Mars
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Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, after Mercury. Named after the Roman god of war, it is referred to as the Red Planet because the iron oxide prevalent on its surface gives it a reddish appearance. Mars is a planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the valleys, deserts, and polar ice caps of Earth. The rotational period and seasonal cycles of Mars are likewise similar to those of Earth, Mars is the site of Olympus Mons, the largest volcano and second-highest known mountain in the Solar System, and of Valles Marineris, one of the largest canyons in the Solar System. The smooth Borealis basin in the northern hemisphere covers 40% of the planet, Mars has two moons, Phobos and Deimos, which are small and irregularly shaped. These may be captured asteroids, similar to 5261 Eureka, a Mars trojan, there are ongoing investigations assessing the past habitability potential of Mars, as well as the possibility of extant life. Future astrobiology missions are planned, including the Mars 2020 and ExoMars rovers, liquid water cannot exist on the surface of Mars due to low atmospheric pressure, which is about 6⁄1000 that of the Earths, except at the lowest elevations for short periods. The two polar ice caps appear to be largely of water. The volume of ice in the south polar ice cap, if melted. On November 22,2016, NASA reported finding a large amount of ice in the Utopia Planitia region of Mars. The volume of water detected has been estimated to be equivalent to the volume of water in Lake Superior, Mars can easily be seen from Earth with the naked eye, as can its reddish coloring. Its apparent magnitude reaches −2.91, which is surpassed only by Jupiter, Venus, the Moon, optical ground-based telescopes are typically limited to resolving features about 300 kilometers across when Earth and Mars are closest because of Earths atmosphere. Mars is approximately half the diameter of Earth with an area only slightly less than the total area of Earths dry land. Mars is less dense than Earth, having about 15% of Earths volume and 11% of Earths mass, the red-orange appearance of the Martian surface is caused by iron oxide, or rust. It can look like butterscotch, other common colors include golden, brown, tan. Like Earth, Mars has differentiated into a metallic core overlaid by less dense materials. Current models of its interior imply a core with a radius of about 1,794 ±65 kilometers, consisting primarily of iron and this iron sulfide core is thought to be twice as rich in lighter elements than Earths. The core is surrounded by a mantle that formed many of the tectonic and volcanic features on the planet
3.
Tharsis
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Tharsis is a vast volcanic plateau centered near the equator in the western hemisphere of Mars. The tallest volcano on the planet, Olympus Mons, is associated with the Tharsis region but is actually located off the western edge of the plateau. The name Tharsis is the Greco-Latin transliteration of the biblical Tarshish, Tharsis can have many meanings depending on historical and scientific context. The name is used in a broad sense to represent a continent-sized region of anomalously elevated terrain centered just south of the equator around longitude 265°E. Called the Tharsis bulge or Tharsis rise, this broad, elevated region dominates the western hemisphere of Mars and is the largest topographic feature on the planet, Tharsis has no formally defined boundaries, so precise dimensions for the region are difficult to give. In general, the bulge is about 5,000 km across and it roughly extends from Amazonis Planitia in the west to Chryse Planitia in the east. The bulge is slightly elongated in the direction, running from the northern flanks of Alba Mons to the southern base of the Thaumasia highlands. Depending on how the region is defined, Tharsis covers 10–30 million km2, the greater Tharsis region consists of several geologically distinct subprovinces with different ages and volcano-tectonic histories. The subdivisions given here are informal and may comprise all or parts of other formally named physiographic features, Tharsis is divided into two broad rises, a northern and a larger southern rise. The northern rise partially overlies sparsely cratered, lowland plains north of the dichotomy boundary and this region is dominated by Alba Mons and its extensive volcanic flows. Alba Mons is a vast, low-lying volcanic construct that is unique to Mars, Alba Mons is so large and topographically distinct that it can almost be treated as an entire volcanic province unto itself. The oldest part of the northern rise consists of a broad ridge that corresponds to the highly fractured terrain of Ceraunius Fossae. The ridge is oriented north-south and forms part of the Noachian-aged basement on which Alba Mons sits, the larger southern portion of Tharsis lies on old cratered highland terrain. Its western boundary is defined by the high lava plains of Daedalia Planum. To the east, the southern Tharsis bulge consists of the vast Syria-Thaumasia block, Syria-Thaumasia is bounded to the north by Noctis Labyrinthus and the western three-quarters of Valles Marineris. It is bounded to the east by a north-south oriented ridge called the Coprates rise and these boundaries enclose a broad high plateau and shallow interior basin that include Syria, Sinai, and Solis Plana. The highest plateau elevations on the Tharsis bulge occur in northern Syria Planum, western Noctis Labyrinthus, between the northern and southern portions of the Tharsis bulge lies a relatively narrow, northeast-trending region that may be considered Tharsis proper or central Tharsis. It is defined by the three massive Tharsis Montes volcanoes, a number of volcanic edifices, and adjacent plains consisting of young lava flows
4.
Shield volcano
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A shield volcano is a type of volcano usually built almost entirely of fluid lava flows. They are named for their low profile, resembling a warriors shield lying on the ground and this is caused by the highly fluid lava they erupt, which travels farther than lava erupted from stratovolcanoes. This results in the accumulation of broad sheets of lava. The shape of shield volcanoes is due to the low viscosity of their mafic lava, Shield volcanoes are built by effusive eruptions, which flow out in all directions to create a shield like that of a warrior. Shield volcano itself is taken from the German term Schildvulkan, examples of pyroclastic shields include Billy Mitchell volcano in Papua New Guinea and the Purico Complex in Chile, an example of a felsic shield is the Big Obsidian Flow in Oregon. Active shield volcanoes experience near-continuous eruptive activity over long periods of time. Mount Everest, by comparison, is 8,848 m in height, the research has not yet been confirmed. Shield volcanoes feature a slope that gradually steepens with elevation before eventually flattening near the summit. In height they are typically about one twentieth their width, although the general form of a typical shield volcano varies little worldwide regional differences exist in their size and morphological characteristics. 4° and an average volume of 1.7 km3. Rift zones are a prevalent feature on shield volcanoes that is rare on other volcanic types, the large, decentralized shape of Hawaiian volcanoes as compared to their smaller, symmetrical Icelandic cousins can be attributed to rift eruptions. Fissure venting is common in Hawaiʻi, most Hawaiian eruptions begin with a wall of fire along a major fissure line before centralizing to a small number of points. These eruptions, the calmest of volcanic events, are characterized by the emission of highly fluid basaltic lavas with low gaseous content. These lavas travel a far greater distance than those of other types before solidifying, forming extremely wide. Low volumes of such lavas layered over long periods of time are what slowly constructs the characteristically low, central-vent eruptions, meanwhile, often take the form of large lava fountains, which can reach heights of hundreds of meters or more. If eruptive rates are enough, they may even form splatter-fed lava flows. Hawaiian eruptions are often extremely long lived, Puʻu ʻŌʻō, a cone of Kilauea, has been erupting continuously since 1983. These lava flows can be anywhere between 2 and 20 m thick, pāhoehoe flows, in contrast, move in more conventional sheets, or by the advancement of lava toes in snaking lava columns. Increasing viscosity on the part of the lava or shear stress on the part of local topography can morph a pāhoehoe flow into an aa one, although most shield volcanoes are by volume almost entirely Hawaiian and basaltic in origin, they are rarely exclusively so
5.
Lava
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Lava is the molten rock expelled by a volcano during an eruption. The resulting rock after solidification and cooling is called lava. The molten rock is formed in the interior of planets, including Earth. The source of the heat melts the rock within the earth is geothermal energy. When first erupted from a vent, lava is a liquid usually at temperatures from 700 to 1,200 °C. A lava flow is an outpouring of lava, which is created during a non-explosive effusive eruption. When it has stopped moving, lava solidifies to form igneous rock, the term lava flow is commonly shortened to lava. Although lava can be up to 100,000 times more viscous than water, lava can flow great distances before cooling and solidifying because of its thixotropic, explosive eruptions produce a mixture of volcanic ash and other fragments called tephra, rather than lava flows. The word lava comes from Italian, and is derived from the Latin word labes which means a fall or slide. The first use in connection with extruded magma was apparently in an account written by Francesco Serao on the eruption of Vesuvius between May 14 and June 4,1737. Serao described a flow of lava as an analogy to the flow of water. The composition of almost all lava of the Earths crust is dominated by silicate minerals, mostly feldspars, olivine, pyroxenes, amphiboles, micas, igneous rocks, which form lava flows when erupted, can be classified into three chemical types, felsic, intermediate, and mafic. These classes are primarily chemical, however, the chemistry of lava also tends to correlate with the temperature, its viscosity. Felsic or silicic lavas such as rhyolite and dacite typically form lava spines, most silicic lava flows are extremely viscous, and typically fragment as they extrude, producing blocky autobreccias. Felsic magmas can erupt at temperatures as low as 650 to 750 °C, unusually hot rhyolite lavas, however, may flow for distances of many tens of kilometres, such as in the Snake River Plain of the northwestern United States. Intermediate or andesitic lavas are lower in aluminium and silica, and usually somewhat richer in magnesium, intermediate lavas form andesite domes and block lavas, and may occur on steep composite volcanoes, such as in the Andes. Poorer in aluminium and silica than felsic lavas, and also commonly hotter, greater temperatures tend to destroy polymerized bonds within the magma, promoting more fluid behaviour and also a greater tendency to form phenocrysts. Higher iron and magnesium tends to manifest as a darker groundmass, mafic or basaltic lavas are typified by their high ferromagnesian content, and generally erupt at temperatures in excess of 950 °C
6.
Mount Olympus
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Mount Olympus is the highest mountain in Greece. It is located in the Olympus Range on the border between Thessaly and Macedonia, between the units of Pieria and Larissa, about 80 km southwest from Thessaloniki. Mount Olympus has 52 peaks, deep gorges, and exceptional biodiversity, the highest peak Mytikas, meaning nose, rises to 2,918 metres. It is one of the highest peaks in Europe in terms of topographic prominence, Olympus was notable in Greek mythology as the home of the Greek gods, on the Mytikas peak. Mount Olympus is also noted for its rich flora with several species. It has been a National Park, the first in Greece, since 1938 and it is also a Worlds Biosphere Reserve. Every year thousands of people visit Olympus to admire its fauna and flora, to tour its slopes, organized mountain refuges and various mountaineering and climbing routes are available to visitors who want to explore it. The usual starting point is the town of Litochoro, on the foothills of the mountain,100 km from Thessaloniki, where, in the beginning of every summer. The shape of Olympus was formed by rain and wind, which produced an isolated tower almost 3,000 metres above the sea, Olympus has many peaks and an almost circular shape. The mountain has a circumference of 150 kilometres, a diameter of 26 kilometres. To the northwest lies the Vlach village of Kokkinoplou, the Makryrema stream separates Olympus from the massif of Voulgara. The villages Petra, Vrontou and Dion lie to the northwest, while on the side there is the town of Litochoro. On its southeastern side, the Ziliana gorge divides Mount Olympus from Kato Olympos, while on its foothills, there are the villages Sykaminea. The Aghias Triadas Sparmou Monastery and the village Pythion lie to the west, Olympus dry foothills are known as the Xirokampi, containing chaparral and small animals. Further east, the plain of Dion is fertile and watered by the streams originate on Olympus. Mount Olympus is formed of rock laid down 200 million years ago in a shallow sea. Various geological events that caused the emergence of the whole region. Around one million years ago glaciers covered Olympus and created its plateaus, the complicated geological past of the region is obvious on the morphology of Olympus and its National Park
7.
Ancient Greece
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Ancient Greece was a civilization belonging to a period of Greek history from the Greek Dark Ages of the 12th-9th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and this was followed by the period of Classical Greece, an era that began with the Greco-Persian Wars, lasting from the 5th to 4th centuries BC. Due to the conquests by Alexander the Great of Macedonia, Hellenistic civilization flourished from Central Asia to the end of the Mediterranean Sea. Classical Greek culture, especially philosophy, had a influence on ancient Rome. For this reason Classical Greece is generally considered to be the culture which provided the foundation of modern Western culture and is considered the cradle of Western civilization. Classical Antiquity in the Mediterranean region is considered to have begun in the 8th century BC. Classical Antiquity in Greece is preceded by the Greek Dark Ages and this period is succeeded, around the 8th century BC, by the Orientalizing Period during which a strong influence of Syro-Hittite, Jewish, Assyrian, Phoenician and Egyptian cultures becomes apparent. The end of the Dark Ages is also dated to 776 BC. The Archaic period gives way to the Classical period around 500 BC, Ancient Periods Astronomical year numbering Dates are approximate, consult particular article for details The history of Greece during Classical Antiquity may be subdivided into five major periods. The earliest of these is the Archaic period, in which artists made larger free-standing sculptures in stiff, the Archaic period is often taken to end with the overthrow of the last tyrant of Athens and the start of Athenian Democracy in 508 BC. It was followed by the Classical period, characterized by a style which was considered by observers to be exemplary, i. e. classical, as shown in the Parthenon. This period saw the Greco-Persian Wars and the Rise of Macedon, following the Classical period was the Hellenistic period, during which Greek culture and power expanded into the Near and Middle East. This period begins with the death of Alexander and ends with the Roman conquest, Herodotus is widely known as the father of history, his Histories are eponymous of the entire field. Herodotus was succeeded by authors such as Thucydides, Xenophon, Demosthenes, Plato, most of these authors were either Athenian or pro-Athenian, which is why far more is known about the history and politics of Athens than those of many other cities. Their scope is limited by a focus on political, military and diplomatic history, ignoring economic. In the 8th century BC, Greece began to emerge from the Dark Ages which followed the fall of the Mycenaean civilization, literacy had been lost and Mycenaean script forgotten, but the Greeks adopted the Phoenician alphabet, modifying it to create the Greek alphabet. The Lelantine War is the earliest documented war of the ancient Greek period and it was fought between the important poleis of Chalcis and Eretria over the fertile Lelantine plain of Euboea. Both cities seem to have suffered a decline as result of the long war, a mercantile class arose in the first half of the 7th century BC, shown by the introduction of coinage in about 680 BC
8.
Arcadia quadrangle
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The Arcadia quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey Astrogeology Research Program. The quadrangle is located in the portion of Mars’ western hemisphere and covers 240° to 300° east longitude. The quadrangle uses a Lambert conformal conic projection at a scale of 1,5,000,000. The Arcadia quadrangle is also referred to as MC-3, the southern and northern borders of the Arcadia quadrangle are approximately 3,065 km and 1,500 km wide, respectively. The north to south distance is about 2,050 km, the quadrangle covers an approximate area of 4.9 million square km, or a little over 3% of Mars’ surface area. The region called Tempe Terra is in the Arcadia quadrangle, several features found in this quadrangle are interesting, especially gullies which are believed to be caused by relatively recent flows of liquid water. Dark slope streaks and dust devil tracks can have a striking appearance, Arcadia is the name of a telescopic albedo feature located at 45° north latitude and 260° east longitude on Mars. The feature was named after a region in southern Greece. The name was approved by the International Astronomical Union in 1958, the quadrangle contains Alba Patera, the largest volcano in the solar system and Tempe Terra, a highly fractured block of ancient crust about the size of Alaska. Large troughs are called fossae in the language used for Mars. This term is derived from Latin, therefore fossa is singular and these troughs form when the crust is stretched until it breaks. The stretching can be due to the weight of a nearby volcano. Fossae/pit craters are common near volcanoes in the Tharsis and Elysium system of volcanoes, a trough often has two breaks with a middle section moving down, leaving steep cliffs along the sides, such a trough is called a graben. Lake George, in northern New York State, is a lake that sits in a graben, pit craters are often associated with graben. Pit craters do not have rims or ejecta around them, like impact craters do, 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 and 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. Other ideas have been suggested for the formation of fossae and pit craters, there is evidence that they are associated with dikes of magma
9.
Mare Acidalium quadrangle
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The Mare Acidalium quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey Astrogeology Research Program. The quadrangle is located in the portion of Mars’ western hemisphere and covers 300° to 360° east longitude. The quadrangle uses a Lambert conformal conic projection at a scale of 1,5,000,000. The Mare Acidalium quadrangle is also referred to as MC-4, the southern and northern borders of the quadrangle are approximately 3,065 km and 1,500 km wide, respectively. The north to south distance is about 2,050 km, the quadrangle covers an approximate area of 4.9 million square km, or a little over 3% of Mars’ surface area. Most of the region called Acidalia Planitia is found in Acidalium quadrangle, parts of Tempe Terra, Arabia Terra, and Chryse Planitia are also in this quadrangle. This area contains many bright spots on a background that may be mud volcanoes. There are also some gullies that are believed to have formed by recent flows of liquid water. Mare Acidalium is the name of a telescopic albedo feature located at 45° N, the feature was named for a well or fountain in Boeotia, Greece. According to classical tradition, it is a location where Venus, the name was approved by the International Astronomical Union in 1958. The quadrangle contains many interesting features, including gullies and possible shorelines of an ancient northern ocean, the boundary between the southern highlands and the northern lowlands lies in Mare Acidalium. The Face on Mars, of great interest to the public, is located near 40.8 degrees north and 9.6 degrees west. When Mars Global Surveyor examined it with high resolution, the turned out to just be an eroded mesa. Mare Acidalium contains the Kasei Valles system of canyons and this huge system is 300 miles wide in some places—Earths Grand Canyon is only 18 miles wide. The HiRISE image below of Acidalia Colles shows gullies in the northern hemisphere, gullies occur on steep slopes, especially craters. Gullies are believed to be relatively young because they have few, if any craters, usually, each gully has an alcove, channel, and apron. Although many ideas have been put forward to them, the most popular involve liquid water either coming from an aquifer or left over from old glaciers. There is evidence for both theories, most of the gully alcove heads occur at the same level, just as one would expect of an aquifer
10.
Saudi Arabia
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Saudi Arabia is bordered by Jordan and Iraq to the north, Kuwait to the northeast, Qatar, Bahrain and the United Arab Emirates to the east, Oman to the southeast and Yemen to the south. It is separated from Israel and Egypt by the Gulf of Aqaba and it is the only nation with both a Red Sea coast and a Persian Gulf coast and most of its terrain consists of arid desert and mountains. The area of modern-day Saudi Arabia formerly consisted of four regions, Hejaz, Najd and parts of Eastern Arabia. The Kingdom of Saudi Arabia was founded in 1932 by Ibn Saud and he united the four regions into a single state through a series of conquests beginning in 1902 with the capture of Riyadh, the ancestral home of his family, the House of Saud. Saudi Arabia has since been a monarchy, effectively a hereditary dictatorship governed along Islamic lines. The ultraconservative Wahhabi religious movement within Sunni Islam has been called the predominant feature of Saudi culture, with its global spread largely financed by the oil and gas trade. Saudi Arabia is sometimes called the Land of the Two Holy Mosques in reference to Al-Masjid al-Haram and Al-Masjid an-Nabawi, the state has a total population of 28.7 million, of which 20 million are Saudi nationals and 8 million are foreigners. The states official language is Arabic, petroleum was discovered on 3 March 1938 and followed up by several other finds in the Eastern Province. Saudi Arabia has since become the worlds largest oil producer and exporter, controlling the second largest oil reserves. The kingdom is categorized as a World Bank high-income economy with a high Human Development Index and is the only Arab country to be part of the G-20 major economies. However, the economy of Saudi Arabia is the least diversified in the Gulf Cooperation Council, the state has attracted criticism for its treatment of women and use of capital punishment. Saudi Arabia is an autocracy, has the fourth highest military expenditure in the world. Saudi Arabia is considered a regional and middle power, in addition to the GCC, it is an active member of the Organisation of Islamic Cooperation and OPEC. Following the unification of the Hejaz and Nejd kingdoms, the new state was named al-Mamlakah al-ʻArabīyah as-Suʻūdīyah by royal decree on 23 September 1932 by its founder, Abdulaziz Al Saud. Although this is translated as the Kingdom of Saudi Arabia in English it literally means the Saudi Arab kingdom. Its inclusion expresses the view that the country is the possession of the royal family. Al Saud is an Arabic name formed by adding the word Al, meaning family of or House of, in the case of the Al Saud, this is the father of the dynastys 18th century founder, Muhammad bin Saud. There is evidence that human habitation in the Arabian Peninsula dates back to about 125,000 years ago
11.
Chryse Planitia
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Chryse Planitia is a smooth circular plain in the northern equatorial region of Mars close to the Tharsis region to the west, centered at 28. 4°N319. 7°E /28.4,319.7. Chryse Planitia lies partially in the Lunae Palus quadrangle, partially in the Oxia Palus quadrangle, the density of impact craters in the 100 to 2,000 metres range is close to half the average for lunar maria. It is one of the lowest regions on Mars, so water would tend to flow into it, the elevation generally goes down from the Tharsis Ridge to Chryse. Kasei Valles, Maja Valles, and Nanedi Valles appear to run from areas to Chryse Planitia. On the other side of Chryse, to the east, the land gets higher, Ares Vallis travels from this high region, then empties into Chryse. Much of Tiu Valles and Simud Valles move toward Chryse as well, several ancient river valleys discovered in Chryse Planitia by the Viking Orbiters, as part of the Viking program, provided strong evidence for a great deal of running water on the surface of Mars. Chryse basin opens into the North Polar Basin, so if an ocean was present Chryse would have been a large bay. The Viking 1 landed in Chryse Planitia, but its site was not near the outflow channels and no fluvial features were visible. The Mars Pathfinder landed in Ares Vallis, at the end of one of the outflow channels emptying into Chryse, list of plains on Mars Geography of Mars Climate of Mars Google Mars scrollable map - centered on Chryse Planitia Martel, L. M. V. Outflow Channels May Make a Case for a Bygone Ocean on Mars
12.
Acidalia Planitia
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Acidalia Planitia is a plain on Mars. It is located between the Tharsis volcanic province and Arabia Terra to the north of Valles Marineris, centered at 49. 8°N339. 3°E /49.8,339.3. Most of this region is found in the Mare Acidalium quadrangle, the plain contains the famous Cydonia region at the contact with the heavily cratered highland terrain. The plain is named after an albedo feature on a map by Giovanni Schiaparelli. Some places in Acidalia Planitia show cones, some researchers have suggested that these are mud volcanoes. Martian gullies are small, incised networks of channels and their associated downslope sediment deposits. 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 an alcove at its head, a fan-shaped apron at its base. They are believed to be relatively young because they have few, a subclass of gullies is also found cut into the faces of sand dunes which are themselves considered to be quite young. However, this remains a topic of active research, in the 2011 novel The Martian by Andy Weir, and its 2015 film adaptation, Acidalia Planitia is the landing site of the Ares III mission, where the protagonist is stranded following a dust storm. Geography of Mars List of plains on Mars Martian Gullies Google Mars zoomable map centered on Acidalia Planitia
Interactive imagemap of the global topography of Mars. Hover your mouse to see the names of over 25 prominent geographic features, and click to link to them. Coloring of the base map indicates relative elevations, based on data from the Mars Orbiter Laser Altimeter on NASA's Mars Global Surveyor. Reds and pinks are higher elevation (+3 km to +8 km); yellow is 0 km; greens and blues are lower elevation (down to −8 km). Whites (>+12 km) and browns (>+8 km) are the highest elevations. Axes are latitude and longitude; Poles are not shown. 
