The surface of

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...

has been divided into thirty cartographic quadrangles by the

United States Geological Survey The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...

. Each quadrangle is a region covering a specified range of

latitude In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pol ...

s and

longitude Longitude (, ) is a geographic coordinate that specifies the east–west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter l ...

s on the Martian surface. The quadrangles are named after

classical albedo features The classical albedo features of Mars are the light and dark features that can be seen on the planet Mars through an Earth-based telescope. Before the age of space probes, several astronomers created maps of Mars on which they gave names to the fe ...

, and they are numbered from one to thirty with the prefix "MC" (for "Mars Chart"), with the numbering running from north to south and from west to east. The quadrangles appear as rectangles on maps based on a

cylindrical map projection In cartography, map projection is the term used to describe a broad set of transformations employed to represent the two-dimensional curved surface of a globe on a plane. In a map projection, coordinates, often expressed as latitude and longitu ...

, but their actual shapes on the curved surface of Mars are more complicated

Saccheri quadrilateral A Saccheri quadrilateral (also known as a Khayyam–Saccheri quadrilateral) is a quadrilateral with two equal sides perpendicular to the base. It is named after Giovanni Gerolamo Saccheri, who used it extensively in his book ''Euclides ab omni na ...

s. The sixteen equatorial quadrangles are the smallest, with surface areas of each, while the twelve mid-latitude quadrangles each cover . The two polar quadrangles are the largest, with surface areas of each.

History

In 1972,

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

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 LC-36B at Cape Canaveral Air ...

mission returned thousands of photographs collectively covering more than 80% of the Martian surface. That year and the next, NASA's

Jet Propulsion Laboratory The Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, United States. Founded in the 1930s by Caltech researchers, JPL is owned by NASA an ...

collaborated with the

Astrogeology Research Program The Astrogeology Science Center is the entity within the United States Geological Survey concerned with the study of planetary geology and planetary cartography. It is housed in the Shoemaker Building in Flagstaff, Arizona. The Center was establ ...

to assemble Mariner's photographs into the first detailed

photomosaic In the field of photographic imaging, a photographic mosaic, also known under the term Photomosaic, is a picture (usually a photograph) that has been divided into (usually equal sized) tiled sections, each of which is replaced with another phot ...

maps of Mars. To organize and subdivide this work, the USGS divided the planet's surface into thirty cartographic quadrangles, each named for

within the respective regions, and the various quadrangles were assigned to geologists at USGS and at American universities for mapping and study. * * As continuing missions to Mars have made increasingly accurate maps available, the

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...

has assigned names to regions of the planet's surface that reflect its actual surface features and geology. These names are also broadly inspired by classical albedo features, with the result that they generally correspond to the names of the arbitrary USGS quadrangles, though larger IAU features frequently span multiple quadrangles.

Quadrangles

The maps below were produced by the ''

Mars Global Surveyor ''Mars Global Surveyor'' (MGS) was an American robotic space probe developed by NASA's Jet Propulsion Laboratory and launched November 1996. MGS was a global mapping mission that examined the entire planet, from the ionosphere down through the a ...

''s

Mars Orbiter Laser Altimeter 260px, MOLA topographic images of the two hemispheres of Mars. This image appeared on the cover of ''Science'' magazine in May 1999. The Mars Orbiter Laser Altimeter (MOLA) was one of five instruments on the ''Mars Global Surveyor'' (MGS) spacecraf ...

; redder colors indicate higher elevations. The maps of the equatorial quadrangles use a

Mercator projection The Mercator projection () is a cylindrical map projection presented by Flemish geographer and cartographer Gerardus Mercator in 1569. It became the standard map projection for navigation because it is unique in representing north as up and sou ...

, while those of the mid-latitude quadrangles use a

Lambert conformal conic projection A Lambert conformal conic projection (LCC) is a conic map projection used for aeronautical charts, portions of the State Plane Coordinate System, and many national and regional mapping systems. It is one of seven projections introduced by Joh ...

, and the maps of the polar quadrangles use a polar

stereographic projection In mathematics, a stereographic projection is a perspective projection of the sphere, through a specific point on the sphere (the ''pole'' or ''center of projection''), onto a plane (geometry), plane (the ''projection plane'') perpendicular to ...

References

{{Portal bar, Solar System *

History

Quadrangles

See also

References