Topographic map of Mars, courtesy NASA Goddard Space Flight Center, from Mars Global Surveyor laser altimeter research led by Maria Zuber and David Smith. Notable features include the Tharsis volcanoes in the west (including Olympus Mons), Valles Marineris to the east of Tharsis, and Hellas Basin in the southern hemisphere.

The "geography" of Mars (also known as Areography) entails the delineation and characterization of regions on Mars. The term areography was sometimes used in the early 20th century to refer to this subject but this term is rarely used today^[1]. Martian geography is mainly focused on what is called physical geography on Earth; that is the distribution of physical features across Mars and their cartographic representations. Topographic Map of Mars; http://photojournal. ... Topographic Map of Mars; http://photojournal. ... Artists conception of Mars Global Surveyor (NASA) The Mars Global Surveyor (MGS) is a US spacecraft developed by NASA and the Jet Propulsion Laboratory and launched November 1996. ... Olympus Mons Olympus Mons (Latin, Mount Olympus) is the tallest known mountain in our solar system, located on the planet Mars at approximately . ... True-color image of the Earths surface and atmosphere Physical geography (also know as geosystems or physiography) is a subfield of geography that focuses on the systematic study of patterns and processes within the hydrosphere, biosphere, atmosphere, and lithosphere. ... Cartography or mapmaking (in Greek chartis = map and graphein = write) is the study, practice, science and art of making maps or globes. ...

History

Map of Mars by Giovanni Schiaparelli.

The first observations of Mars were, of course, from land-based telescopes. The history of these observations are marked by the oppositions of Mars, when the planet is closest to Earth and hence is most easily visible, which occur every couple of years. Even more notable are the perihelic oppositions of Mars which occur approximately every 16 years, and are distiguished because Mars is close to perihelion making it even closer to Earth. Image File history File links Karte_Mars_Schiaparelli_MKL1888. ... Image File history File links Karte_Mars_Schiaparelli_MKL1888. ... 50 cm refracting telescope at Nice Observatory. ... Opposition is a term used in positional astronomy and astrology to indicate when one celestial body is on the opposite side of the sky when viewed from a particular place (usually the Earth). ... A diagram of Keplerian orbital elements. ...

In September 1877, (a perihelic opposion of Mars occurred on September 5), Italian astronomer Giovanni Schiaparelli published the first detailed map of Mars. These maps notably contained features he called canali ("channels"), that were later shown to be an optical illusion. These canali were supposedly long straight lines on the surface of Mars to which he gave names of famous rivers on Earth. His term was popularly mistranslated as canals, and so started the Martian canal controversy. 1877 (MDCCCLXXVII) was a common year starting on Monday (see link for calendar). ... September 5 is the 248th day of the year (249th in leap years). ... Giovanni Virginio Schiaparelli (March 14, 1835 – July 4, 1910) was an Italian astronomer. ... Note: This article contains special characters. ... An optical illusion is characterized by visually perceived images that, at least in common sense terms, are deceptive or misleading. ... For a time in the late 19th and early 20th centuries, it was believed that there were canals on Mars. ...

Following these observations, it was a long held belief that Mars contained vast seas and vegetation. It was not until spacecraft visited the planet during NASA's Mariner missions in the 1960s that these myths were dispelled. Some maps of Mars were made using the data from these missions, but it wasn't until the Mars Global Surveyor mission, launched in 1996 and still operational as of 2006, that complete, extremely detailed maps were obtained. These maps are now available online at http://www.google.com/mars/ A spacecraft is a vehicle, vessel, craft or device designed to operate beyond the surface of the Earth in outer space. ... NASA Insignia Listen to this article · (info) This audio file was created from an article revision dated 2005-09-01, and does not reflect subsequent edits to the article. ... Launch of Mariner 1 (NASA) The Mariner program was a series of unmanned interplanetary probes designed to investigate Mars, Venus and Mercury. ... Artists conception of Mars Global Surveyor (NASA) The Mars Global Surveyor (MGS) is a US spacecraft developed by NASA and the Jet Propulsion Laboratory and launched November 1996. ... 1996 (MCMXCVI) was a leap year starting on Monday of the Gregorian calendar, and was designated the International Year for the Eradication of Poverty. ... 2006 (MMVI) is a common year starting on Sunday of the Gregorian calendar. ...

Topography

Elevation map of Mars based on Mars Global Surveyor data

Mars, 2001, with polar ice caps visible.

North Polar region with icecap. (Courtesy NASA/JPL-Caltech.)

The dichotomy of Martian topography is striking: northern plains flattened by lava flows contrast with the southern highlands, pitted and cratered by ancient impacts. The surface of Mars as seen from Earth is consequently divided into two kinds of areas, with differing albedo. The paler plains covered with dust and sand rich in reddish iron oxides were once thought of as Martian 'continents' and given names like Arabia Terra (land of Arabia) or Amazonis Planitia (Amazonian plain). The dark features were thought to be seas, hence their names Mare Erythraeum, Mare Sirenum and Aurorae Sinus. The largest dark feature seen from Earth is Syrtis Major. Image File history File links Download high resolution version (4000x2769, 1082 KB) Summary Levantamento topográfico realizado pela sonda norte-americana Mars Global Surveyor Licensing File links The following pages link to this file: Mars ... Image File history File links Download high resolution version (4000x2769, 1082 KB) Summary Levantamento topográfico realizado pela sonda norte-americana Mars Global Surveyor Licensing File links The following pages link to this file: Mars ... Image File history File links Mars_Hubble. ... Image File history File links Mars_Hubble. ... North Polar region of Mars; http://photojournal. ... North Polar region of Mars; http://photojournal. ... Albedo is a ratio of scattered to incident electromagnetic radiation power. ... Arabia Terra is large upland region in the north of Mars. ... Amazonis Planitia is one of the smoothest plains on Mars. ... Mare Erythraeum is a dark dusky region of Mars that can be viewed by even a small telescope. ... a like dark place in the sky. ... Syrtis Major is a dark spot (an albedo feature) located in the boundary between the northern lowlands and southern highlands of Mars. ...

The shield volcano, Olympus Mons (Mount Olympus), is at 26 km the highest known mountain in the solar system. It is in a vast upland region called Tharsis, which contains several large volcanos. See list of mountains on Mars. The Tharsis region of Mars also has the solar system's largest canyon system, Valles Marineris or the Mariner Valley, which is 4000 km long and 7 km deep. Mars is also scarred by a number of impact craters. The largest of these is the Hellas impact basin, covered with light red sand. See list of craters on Mars. Shield volcano Mauna Kea, a shield volcano, on the Island of Hawai‘i with a light dusting of snow. ... Volcano 1. ... Olympus Mons Olympus Mons (Latin, Mount Olympus) is the tallest known mountain in our solar system, located on the planet Mars at approximately . ... Clouds hover over the volcano peaks of the Tharsis region in this color mosaic image. ... This is a list of all the named mountains on Mars. ... Valles Marineris cuts a wide swath across the face of Mars Valles Marineris (Latin for Mariner Valley, named after the Mariner 9 Mars orbiter of 1971-72 which discovered it. ... Launch of Mariner 1 (NASA) The Mariner program was a series of unmanned interplanetary probes designed to investigate Mars, Venus and Mercury. ... Tycho crater on Earths moon. ... NASA image of Hellas Planitia Hellas Planitia, also known as the Hellas Impact Basin, is a roughly circular impact crater located in the southern hemisphere of the planet Mars. ... There are hundreds of thousands of craters on Mars, but only some of them have names. ...

Mars has two permanent polar ice caps, the northern one located at Planum Boreum and the southern one at Planum Australe. Viking mosaic of Planum Boreale and surrounds. ... Planum Australe, taken by Mars Global Surveyor. ...

The difference between Mars' highest and lowest points is nearly 31 km (from the top of Olympus Mons at an altitude of 26 km to the bottom of the Hellas impact basin at an altitude of 4 km below the datum). In comparison, the difference between Earth's highest and lowest points (Mount Everest and the Mariana Trench) is only 19.7 km. Combined with the planets' different radii, this means Mars is nearly three times "rougher" than Earth. Everest redirects here. ... Mariana Trench location This article is about the geographical feature. ...

The International Astronomical Union's Working Group for Planetary System Nomenclature is responsible for naming Martian surface features. Logo of the IAU The International Astronomical Union (French: Union astronomique internationale) unites national astronomical societies from around the world. ...

Zero elevation

Since Mars has no oceans and hence no 'sea level', it is convenient to define an arbitrary zero-elevation level or "datum" for mapping the surface. The datum for Mars is defined in terms of the height at which the air has a particular pressure at about the freezing point of water: a pressure of 610.5 Pa (6.105 mbar), approximately 0.6% of Earth's, at a temperature of 273.16 K. This pressure and temperature correspond to the triple point of water. Conditions on Mars are so different from those on Earth that Martian altitude readings should not be directly compared to Earthly ones for purposes of finding life, potential colony sites, etc.. It has been suggested that this article or section be merged with Geodetic system. ... In physics, the triple point of a substance is the temperature and pressure at which three phases (gas, liquid, and solid) of that substance may coexist in thermodynamic equilibrium. ...

Zero meridian

Mars' equator is defined by its rotation, but the location of its Prime Meridian was specified, as was Earth's, by choice of an arbitrary point which was accepted by later observers. The German astronomers Wilhelm Beer and Johann Heinrich Mädler selected a small circular feature as a reference point when they produced the first systematic chart of Mars features in 1830-32. In 1877, their choice was adopted as the prime meridian by the Italian astronomer Giovanni Schiaparelli when he began work on his notable maps of Mars. After the spacecraft Mariner 9 provided extensive imagery of Mars in 1972, a small crater (later called Airy-0), located in the Sinus Meridiani ('Middle Bay' or 'Meridian Bay') along the line of Beer and Mädler, was chosen by Merton Davies of the RAND Corporation to provide a more precise definition of 0.0° longitude when he established a planetographic control point network. Location of the Prime Meridian Prime Meridian in Greenwich The Prime Meridian, also known as the International Meridian or Greenwich Meridian, is the meridian (line of longitude) passing through the Royal Greenwich Observatory, Greenwich, England — it is the meridian at which longitude is 0 degrees. ... Wilhelm Beer Wilhelm Wolff Beer (January 14, 1797 – March 27, 1850) was a banker and astronomer in Berlin, Germany, and brother of Giacomo Meyerbeer. ... J. H. von Mädler. ... Giovanni Virginio Schiaparelli (March 14, 1835 – July 4, 1910) was an Italian astronomer. ... Mariner 9 launch Mariner 9 was a NASA space probe orbiter that helped in the exploration of Mars and was part of the Mariner program. ... Airy-0 is a crater on Mars whose location defines the position of the prime meridian of that planet. ... Sinus Meridiani is a classic albedo feature on Mars stretching east-west just south of that planets equator. ... RAND Headquarters The RAND Corporation is a global policy think tank first formed to offer research and analysis to the United States armed forces. ...

Nomenclature

Early nomenclature

Although better remembered for mapping the Moon starting in 1830, Johann Heinrich Mädler and Wilhelm Beer were the first "areographers". They started off by establishing once and for all that most of the surface features were permanent, and pinned down Mars' rotation period. In 1840, Mädler combined ten years of observations and drew the first map of Mars ever made. Rather than giving names to the various markings they mapped, Beer and Mädler simply designated them with letters; Meridian Bay (Sinus Meridiani) was thus feature "a". Adjective lunar Bulk silicate composition (estimated wt%) SiO2 44. ... J. H. von Mädler. ... Wilhelm Beer Wilhelm Wolff Beer (January 14, 1797 – March 27, 1850) was a banker and astronomer in Berlin, Germany, and brother of Giacomo Meyerbeer. ...

Over the next twenty years or so, as instruments improved and the number of observers also increased, various Martian features acquired a hodge-podge of names. To give a couple of examples, Solis Lacus was known as the "Oculus" (the Eye), and Syrtis Major was usually known as the "Hourglass Sea" or the "Scorpion". In 1858, it was also dubbed the "Atlantic Canale" by the Jesuit astronomer Angelo Secchi. Secchi commented that it "seems to play the role of the Atlantic which, on Earth, separates the Old Continent from the New" —this was the first time the fateful canale, which in Italian can mean either "channel" or "canal", had been applied to Mars. Solis Lacus (85° W, 26° S) is a dark feature on Mars. ... Syrtis Major is a dark spot (an albedo feature) located in the boundary between the northern lowlands and southern highlands of Mars. ... Pietro Angelo Secchi (1818–1878) was an Italian astronomer. ...

In 1867, Richard Anthony Proctor drew up a map of Mars based, somewhat crudely, on the Rev. William Rutter Dawes' earlier drawings of 1865, then the best ones available. Proctor explained his system of nomenclature by saying, "I have applied to the different features the names of those observers who have studied the physical peculiarities presented by Mars." Here are some of his names, paired with those later proposed by Schiaparelli: Richard Anthony Proctor Richard Anthony Proctor (March 23, 1837 – September 12, 1888), British astronomer, was born at Chelsea. ... William Rutter Dawes (March 19, 1799 – February 15, 1868) was a British astronomer. ... Giovanni Virginio Schiaparelli (March 14, 1835 – July 4, 1910) was an Italian astronomer. ...

• Kaiser Sea = Syrtis Major
• Lockyer Land = Hellas Planitia
• Main Sea = Lacus Moeris
• Herschel II Strait = Sinus Sabaeus
• Dawes Continent = Aeria and Arabia
• De La Rue Ocean = Mare Erythraeum
• Lockyer Sea = Solis Lacus
• Dawes Sea = Tithonius Lacus
• Madler Continent = Chryse Planitia, Ophir, Tharsis
• Maraldi Sea = Maria Sirenum and Cimmerium
• Secchi Continent = Memnonia
• Hooke Sea = Mare Tyrrhenum
• Cassini Land = Ausonia
• Herschel I Continent = Zephyria, Aeolis, Aethiopis
• Hind Land = Libya

Proctor's nomenclature has often been criticized, mainly because so many of his names honored English astronomers, but also because he used many names more than once. In particular, Dawes appeared no fewer than six times (Dawes Ocean, Dawes Continent, Dawes Sea, Dawes Strait, Dawes Isle, and Dawes Forked Bay). Even so, Proctor's names are not without charm, and for all their shortcomings they were a foundation on which later astronomers would improve. Syrtis Major is a dark spot (an albedo feature) located in the boundary between the northern lowlands and southern highlands of Mars. ... NASA image of Hellas Planitia Hellas Planitia, also known as the Hellas Impact Basin, is a roughly circular impact crater located in the southern hemisphere of the planet Mars. ... Mare Erythraeum is a dark dusky region of Mars that can be viewed by even a small telescope. ... Solis Lacus (85° W, 26° S) is a dark feature on Mars. ... Chryse Planitia is a smooth circular plain in the northern equatorial region of Mars close to the Tharsis region. ... Ophir may refer to: Ophir, a region mentioned in the Bible that was famous for its wealth. ... Clouds hover over the volcano peaks of the Tharsis region in this color mosaic image. ... Memnonia quadrangle is a region of Mars that covers Latitude -35° to 35° and Longitute 210° to 150°. Mangala Vallis is located in the upland region of Memnonia. ... Ausonia is a Greek and Virgilian poetical name for Italy (Aeneid vii. ... Aeolis (Aiolis) or Aeolia (Aiolia) was an area in west and northwest Asia Minor, mostly along the coast and offshore islands (particularly Lesbos), where the Aeolian Greek city-states were located. ... The Aithiopis (Greek: Αἰθιοπίς; Latin: Aethiopis) is a lost epic of ancient Greek literature. ... William Rutter Dawes (March 19, 1799 – February 15, 1868) was a British astronomer. ...

Modern nomenclature

Today, features on Mars derive from a number of sources. Large albedo features retain many of the older names, but are often updated to reflect new knowledge of the nature of the features. For example 'Nix Olympica' (the snows of Olympus) has become Olympus Mons (Mount Olympus). Albedo is a ratio of scattered to incident electromagnetic radiation power. ... Olympus Mons Olympus Mons (Latin, Mount Olympus) is the tallest known mountain in our solar system, located on the planet Mars at approximately . ...

Large Martian craters are named after important scientists and science fiction writers; smaller ones are named after towns and villages on Earth.

Various landforms studied by the Mars Exploration Rover are given temporary names or nicknames to identify and marker them, however certain major features such as the Columbia Hills were named after the seven astronauts of the Space Shuttle Columbia disaster, and the hope is that the names are made permanent by the International Astronomical Union. Artists Concept of Rover on Mars (credit: Maas Digital LLC) NASAs Mars Exploration Rover (MER) Mission is an ongoing unmanned Mars exploration mission, commenced in 2003, that sent two robotic rovers Spirit and Opportunity to explore the Martian surface and geology. ... The view of Columbia Hills from the MER-A landing site The Columbia Hills are a range of low hills inside Gusev crater on Mars. ... The Space Shuttle Columbia breaks up over Texas. ... Logo of the IAU The International Astronomical Union (French: Union astronomique internationale) unites national astronomical societies from around the world. ...

See also

• Geology of Mars
• Category:Surface features of Mars - Category of various surface features on Mars

The geology of Mars, sometimes called areology, is the study of its composition, structure, physical properties, history and the processes that shape it. ...

References

1. ^ Cartographic Inscription and Exploration Narrative in Late Victorian Representations of the Red Planet

• Sheehan, William, "The Planet Mars: A History of Observation and Discovery" (Full text online) The University of Arizona Press, Tucson. 1996.

External links

• Google Mars - Google Maps for Mars, with various surface features and interesting places pointed out