The following outline is provided as an overview of and topical guide to Mars: Mars – fourth planet from the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

and the second-smallest planet in the Solar System, after Mercury. Named after the Roman god of war, it is often referred to as the "Red Planet" because the

iron oxide Iron oxides are chemical compounds composed of iron and oxygen. Several iron oxides are recognized. All are black magnetic solids. Often they are non-stoichiometric. Oxyhydroxides are a related class of compounds, perhaps the best known of which ...

prevalent on its surface gives it a reddish appearance. Mars is a terrestrial planet with a thin

atmosphere An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A s ...

, having surface features reminiscent both of the impact craters of the Moon and the valleys, deserts, and

polar ice caps A polar ice cap or polar cap is a high-latitude region of a planet, dwarf planet, or natural satellite that is covered in ice. There are no requirements with respect to size or composition for a body of ice to be termed a polar ice cap, no ...

of Earth.

Classification of Mars

Astronomical object An astronomical object, celestial object, stellar object or heavenly body is a naturally occurring physical entity, association, or structure that exists in the observable universe. In astronomy, the terms ''object'' and ''body'' are often u ...

** Gravitationally rounded object *** Planet **** Planet of the Solar System *****

Inner planet The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...

*****

Superior planet In the Solar System, a planet is said to be inferior or interior with respect to another planet if its orbit lies inside the other planet's orbit around the Sun. In this situation, the latter planet is said to be superior to the former. In the ref ...

**** Terrestrial planet

Location of Mars

* Milky Way Galaxy – barred spiral galaxy **

Orion Arm The Orion Arm is a minor spiral arm of the Milky Way Galaxy that is across and approximately in length, containing the Solar System, including Earth. It is also referred to by its full name, the Orion–Cygnus Arm, as well as Local Arm, Orion ...

– a spiral arm of the Milky Way *** Solar System – the Sun and the objects that orbit it, including 8 planets, the 4th planet from the Sun being Mars ****

Orbit of Mars Mars has an orbit with a semimajor axis of 1.524 astronomical units (228 million km), and an eccentricity of 0.0934.Jean Meeus, ''Astronomical Formulæ for Calculators''. (Richmond, VA: Willmann-Bell, 1988) 99. Elements by F. E. Ross The planet ...

Features of Mars

Atmosphere of Mars The atmosphere of Mars is the layer of gases surrounding Mars. It is primarily composed of carbon dioxide (95%), molecular nitrogen (2.8%), and argon (2%). It also contains trace levels of water vapor, oxygen, carbon monoxide, hydrogen, and n ...

** Circulation *

Climate of Mars The climate of Mars has been a topic of scientific curiosity for centuries, in part because it is the only terrestrial planet whose surface can be directly observed in detail from the Earth with help from a telescope. Although Mars is smaller t ...

Martian surface The study of surface characteristics (or surface properties and processes) is a broad category of Mars science that examines the nature of the materials making up the Martian surface. The study evolved from telescopic and remote-sensing techniques ...

Geography of Mars Areography, also known as the geography of Mars, is a subfield of planetary science that entails the delineation and characterization of regions on Mars. Areography is mainly focused on what is called physical geography on Earth; that is the di ...

***

Outflow channels Outflow channels are extremely long, wide swathes of scoured ground on Mars. They extend many hundreds of kilometers in length and are typically greater than one kilometer in width. They are thought to have been carved by huge outburst floods. ...

Geology of Mars The geology of Mars is the scientific study of the surface, crust, and interior of the planet Mars. It emphasizes the composition, structure, history, and physical processes that shape the planet. It is analogous to the field of terrestrial g ...

***

Martian dichotomy The most conspicuous feature of Mars is a sharp contrast, known as the Martian dichotomy, between the Southern and the Northern hemispheres. The two hemispheres' geography differ in elevation by 1 to 3 km. The average thickness of the Marti ...

***

Martian polar ice caps The planet Mars has two permanent polar ice caps. During a pole's winter, it lies in continuous darkness, chilling the surface and causing the deposition of 25–30% of the atmosphere into slabs of CO2 ice (dry ice). When the poles are again e ...

Solar eclipses on Mars The two moons of Mars, Phobos and Deimos, are much smaller than Earth's Moon, greatly reducing the frequency of solar eclipses on that planet. Neither moon's apparent diameter is large enough to cover the disk of the Sun, and therefore they ar ...

Surface of Mars

Concentric crater fill A concentric crater fill (CCF) is a landform where the floor of a crater is mostly covered with many parallel ridges. It is common in the mid-latitudes of Mars, and is widely believed to be caused by glacial movement. Areas on Mars called Deutero ...

Dark slope streak Dark slope streaks are narrow, avalanche-like features common on dust-covered slopes in the equatorial regions of Mars.Chuang, F.C.; Beyer, R.A.; Bridges, N.T. (2010). Modification of Martian Slope Streaks by Eolian Processes. ''Icarus,'' 205 154 ...

Dust Devil Tracks Martian dust devils (dust devils on Mars) were first photographed by the Viking orbiters in the 1970s. In 1997, the Mars Pathfinder lander detected a dust devil passing over it. In the first image below, photographed by the Mars Global Surveyor, ...

Lineated valley fill Lineated valley fill (LVF), also called lineated floor deposit, is a feature of the floors of some channels on Mars, exhibiting ridges and grooves that seem to flow around obstacles. Shadow measurements show that at least some of the ridges are sev ...

* Mars surface color *

Martian geyser Martian geysers (or jets) are putative sites of small gas and dust eruptions that occur in the south polar region of Mars during the spring thaw. "Dark dune spots" and "spiders" – or araneiforms – are the two most visible types of featur ...

* Martian soil *

Scalloped topography Scalloped topography is common in the mid-latitudes of Mars, between 45° and 60° north and south. It is particularly prominent in the region of Utopia Planitia, in the northern hemisphere, and in the region of Peneus and Amphitrites Paterae in th ...

Seasonal flows on warm Martian slopes Seasonal flows on warm Martian slopes (also called recurring slope lineae, recurrent slope lineae and RSL) are thought to be salty water flows occurring during the warmest months on Mars, or alternatively, dry grains that "flow" downslope of at le ...

Swiss cheese features Swiss cheese features (SCFs) are curious pits in the south polar ice cap of Mars ( Mare Australe quadrangle) named from their similarity to the holes in Swiss cheese. They were first seen in 2000 using Mars Orbiter Camera imagery. Description ...

Valley networks (Mars) Valley networks are branching networks of valleys on Mars that superficially resemble terrestrial river drainage basins.Carr, M.H. (2006), The Surface of Mars. Cambridge Planetary Science Series, Cambridge University Press. They are found mainly ...

* Water on Mars ** Glaciers on Mars **

Groundwater on Mars During past ages, there was rain and snow on Mars; especially in the Noachian and early Hesperian epochs. Some moisture entered the ground and formed aquifers. That is, the water went into the ground, seeped down until it reached a formation tha ...

Landforms on Mars

Martian chaos terrain Chaos terrain on Mars is distinctive; nothing on Earth compares to it. Chaos terrain generally consists of irregular groups of large blocks, some tens of kilometers across and a hundred or more meters high. The tilted and flat topped blocks form ...

Areas of chaos terrain on Mars This is a list of areas of chaos terrain officially named by the International Astronomical Union on the planet Mars. Chaos terrain (or chaotic terrain) is an astrogeological term used to denote planetary surface areas where features such as ridge ...

* Chasmata on Mars * Craters on Mars *

Gullies on Mars 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 ...

* Labes on Mars *

Mountains on Mars A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher ...

* Quadrangles on Mars *

Plains on Mars In geography, a plain is a flat expanse of land that generally does not change much in elevation, and is primarily treeless. Plains occur as lowlands along valleys or at the base of mountains, as coastal plains, and as plateaus or uplands. I ...

* Valles on Mars * Surface features of Mars seen by the Spirit rover

Natural satellites of Mars

Moons of Mars * Phobos **

Phobos monolith The Phobos monolith is a large rock on the surface of Mars's moon Phobos. It is a boulder about across and tall. A monolith is a geological feature consisting of a single massive piece of rock. Monoliths also occur naturally on Earth, but it ...

Transit of Phobos from Mars A transit of Phobos across the Sun as seen from Mars takes place when Phobos (moon), Phobos passes directly between the Sun and a point on the surface of Mars, obscuring a large part of the Sun's disc for an observer on Mars. During a astronomi ...

Deimos Deimos, a Greek word for ''dread'', may refer to: * Deimos (deity), one of the sons of Ares and Aphrodite in Greek mythology * Deimos (moon), the smaller and outermost of Mars' two natural satellites * Elecnor Deimos, a Spanish aerospace company * ...

History of Mars

History of Mars observation The history of Mars observation is about the recorded history of observation of the planet Mars. Some of the early records of Mars' observation date back to the era of the ancient Egyptian astronomers in the 2nd millennium BCE. Chinese records ...

* Martian canals ** List of Martian canals *

Classical albedo features on Mars 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 f ...

* Timeline of discoveries of water on Mars **

Lakes on Mars In summer 1965, the first close-up images from Mars showed a cratered desert with no signs of water. However, over the decades, as more parts of the planet were imaged with better cameras on more sophisticated satellites, Mars showed evidence ...

Exploration of Mars

Exploration of Mars *

Mars aircraft A Mars aircraft is a vehicle capable of sustaining powered flight in the atmosphere of Mars. So far, the Mars Helicopter Ingenuity, Mars helicopter ''Ingenuity'' is the only aircraft ever to fly on Mars, completing 61 successful flights coverin ...

* Mars analogs * Artificial objects on Mars *

Mars atmospheric entry Mars atmospheric entry is the entry into the atmosphere of Mars. High velocity entry into Martian air creates a CO2-N2 plasma, as opposed to O2-N2 for Earth air.

* Mars Direct *

Mars Exploration Joint Initiative The Mars Exploration Joint Initiative (MEJI) is an agreement signed between United States' space agency, NASA, and Europe's space agency, ESA to join resources and expertise in order to continue the exploration of the planet Mars. The agreement w ...

Mars flyby A Mars flyby is a movement of spacecraft passing in the vicinity of the planet Mars, but not entering Orbit (celestial mechanics), orbit or landing on it. Page 15-16 in Chapter 3 of David S. F. Portree's ''Humans to Mars: Fifty Years of Mission Pl ...

Mars landing A Mars landing is a landing of a spacecraft on the surface of Mars. Of multiple attempted Mars landings by robotic, uncrewed spacecraft, ten have had successful soft landings. There have also been studies for a possible human mission to Mars, ...

* Life on Mars * Martian meteorite * Mars Ocean Hypothesis *

Rocks on Mars This is an alphabetical list of named rocks (and meteorites) found on Mars, by mission. This list is a sampling of rocks viewed, and is not an exhaustive listing. A more complete listing may be found on the various NASA mission web sites. This lis ...

* Mars rover * Mars Scout Program

Flyby and direct missions to explore Mars

Missions to Mars *

Mars program The Mars program was a series of uncrewed spacecraft launched by the Soviet Union between 1960 and 1973. The spacecraft were intended to explore Mars, and included flyby probes, landers and orbiters. Early Mars spacecraft were small, and launc ...

Mars 1 Mars 1 Mars 1, also known as 1962 Beta Nu 1, Mars 2MV-4 and Sputnik 23, was an automatic interplanetary station launched in the direction of Mars on November 1, 1962, the first of the Soviet Mars probe program, with the intent of flying by the ...

** Mars 2 ** Mars 3 *

Mariner program The Mariner program was conducted by the American space agency NASA to explore other planets. Between 1962 and late 1973, NASA's Jet Propulsion Laboratory (JPL) designed and built 10 robotic interplanetary probes named Mariner to explore the ...

Mariner 3 Mariner 3 (together with Mariner 4 known as Mariner-Mars 1964) was one of two identical deep-space probes designed and built by the Jet Propulsion Laboratory (JPL) for NASA's Mariner-Mars 1964 project that were intended to conduct close-up (fly ...

Mariner 4 Mariner 4 (together with Mariner 3 known as Mariner-Mars 1964) was the fourth in a series of spacecraft intended for planetary exploration in a flyby mode. It was designed to conduct closeup scientific observations of Mars and to transmit the ...

** Mariner 6 and 7 **

Mariner 8 Mariner-H (Mariner Mars '71), also commonly known as Mariner 8, was (along with Mariner 9) part of the Mariner Mars '71 project. It was intended to go into Mars orbit and return images and data, but a launch vehicle failure prevented Mariner 8 ...

** Mariner 9 *

Zond program Zond (russian: Зонд, lit=probe) was the name given to two distinct series of Soviet robotic spacecraft launched between 1964 and 1970. The first series, based on the 3MV planetary probe, was intended to gather information about nearby plan ...

Zond 2 Zond 2 was a Soviet space probe, a member of the Zond program, and was the sixth Soviet spacecraft to attempt a flyby of Mars. (See Exploration of Mars) It was launched on November 30, 1964 at 13:12 UTC onboard Molniya 8K78 launch vehicle from ...

Viking program The ''Viking'' program consisted of a pair of identical American space probes, ''Viking 1'' and ''Viking 2'', which landed on Mars in 1976. Each spacecraft was composed of two main parts: an orbiter designed to photograph the surface of Mars f ...

** '' Viking 1'' ** ''

Viking 2 The ''Viking 2'' mission was part of the American Viking program to Mars, and consisted of an orbiter and a lander essentially identical to that of the ''Viking 1'' mission. ''Viking 2'' was operational on Mars for sols ( days; '). The ''Vik ...

'' *

Phobos program Phobos (Greek for "fear") most commonly refers to: * Phobos (moon), a moon of Mars * Phobos (mythology) Phobos ( grc, Φόβος, , Ancient Greek: "fear") is the god and personification of fear and panic in Greek mythology. Phobos was the s ...

* ''

Mars Observer The ''Mars Observer'' spacecraft, also known as the ''Mars Geoscience/Climatology Orbiter'', was a robotic space probe launched by NASA on September 25, 1992, to study the Martian surface, atmosphere, climate and magnetic field. During the int ...

'' * '' Mars Pathfinder'' ** ''

Sojourner A sojourner is a person who resides temporarily in a place. Sojourner may also refer to: *Sojourner Truth (1797–1883), abolitionist and women's rights activist *Albert Sojourner (1872–1951), member of the Mississippi House of Representatives ...

'' *

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 ...

Mars Climate Orbiter The ''Mars Climate Orbiter'' (formerly the Mars Surveyor '98 Orbiter) was a robotic space probe launched by NASA on December 11, 1998, to study the Martian climate, Martian atmosphere, and surface changes and to act as the communications rela ...

Mars Polar Lander The Mars Polar Lander, also known as the Mars Surveyor '98 Lander, was a 290-kilogram robotic spacecraft lander launched by NASA on January 3, 1999, to study the soil and climate of Planum Australe, a region near the south pole on Mars. It form ...

Deep Space 2 Deep Space 2 was a NASA space probe, part of the New Millennium Program. It included two highly advanced miniature space probes that were sent to Mars aboard the Mars Polar Lander in January 1999. The probes were named "Scott" and "Amundsen", in ...

2001 Mars Odyssey ''2001 Mars Odyssey'' is a robotic spacecraft orbiting the planet Mars. The project was developed by NASA, and contracted out to Lockheed Martin, with an expected cost for the entire mission of US$297 million. Its mission is to use spectro ...

* ''Nozomi'' spacecraft * Mars Express **

Beagle 2 The ''Beagle 2'' is an inoperative British Mars lander that was transported by the European Space Agency's 2003 ''Mars Express'' mission. It was intended to conduct an astrobiology mission that would have looked for evidence of past life on Mar ...

Mars Exploration Rover NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, '' Spirit'' and '' Opportunity'', exploring the planet Mars. It began in 2003 with the launch of the two rovers to explore the Martian surface ...

** ''Spirit'' rover ** ''Opportunity'' rover * Mars Reconnaissance Orbiter * ''Rosetta'' spacecraft * ''Phoenix'' spacecraft * ''Dawn'' spacecraft * Mars Science Laboratory ** ''Curiosity'' rover * MAVEN *

Mars Orbiter Mission The Mars Orbiter Mission (MOM), also called ''Mangalyaan'', was a space probe orbiting Mars since 24 September 2014. It was launched on 5 November 2013 by the Indian Space Research Organisation (ISRO). It was India's first interplanetary mis ...

* Exomars Program **

ExoMars Trace Gas Orbiter The ExoMars Trace Gas Orbiter (TGO or ExoMars Orbiter) is a collaborative project between the European Space Agency (ESA) and the Russian Roscosmos agency that sent an atmospheric research orbiter and the ''Schiaparelli'' demonstration lander ...

** ''Schiaparelli'' lander * Insight lander *

Mars 2020 Mars 2020 is a Mars rover mission forming part of NASA's Mars Exploration Program that includes the rover '' Perseverance'', the small robotic, coaxial helicopter '' Ingenuity'', and associated delivery vehicles. Mars 2020 was launched from E ...

** ''Perseverance'' rover ** ''Ingenuity'' helicopter *

Emirates Mars Mission , ''Al-Amal'') , manufacturer = , dry_mass = 550 kg , launch_mass = 1350 kg, including800 kg hydrazine fuel1,350 kg , payload_mass = , dimensions = 2.37 m × 2.90 m , power = 1800 watts from t ...

Tianwen-1 -1 (TW-1; zh, t=, s=, l='Heavenly Questions') is an interplanetary mission by the China National Space Administration (CNSA) which sent a robotic spacecraft to Mars, consisting of 6 spacecraft: an orbiter, two deployable cameras, lander, rem ...

Orbiter **

Deployable Camera **

lander ** ''Zhurong'' rover

Proposed missions to explore Mars

ExoMars ExoMars (Exobiology on Mars) is an astrobiology programme of the European Space Agency (ESA). The goals of ExoMars are to search for signs of past life on Mars, investigate how the Martian water and geochemical environment varies, investigate ...

** Kazachok Lander Platform ** ''Rosalind Franklin'' rover *

Mars sample return mission A Mars sample-return (MSR) mission is a proposed mission to collect rock and dust samples on Mars and return them to Earth. Such a mission would allow more extensive analysis than that allowed by onboard sensors. The three most recent concept ...

Human mission to Mars The idea of sending humans to Mars has been the subject of aerospace engineering and scientific studies since the late 1940s as part of the broader exploration of Mars. Some have also considered exploring the Martian moons of Phobos (moon), Phob ...

List of crewed Mars mission plans This list of crewed Mars mission plans is a listing of concept studies for a crewed mission to Mars during the 20th and 21st centuries. It is limited to studies done with engineering and scientific knowledge about the capabilities of then curr ...

Mars Outpost Mars Outpost is a concept for a human base on the planet Mars that was developed by the United States in the 1980s. The components and design were based on an earlier lunar test bed outpost. Development would go through several phases over fou ...

** Mars to Stay **

Colonization of Mars Colonization or settlement of Mars is the theoretical human migration and long-term human establishment of Mars. The prospect has garnered interest from public space agencies and private corporations and has been extensively explored in scien ...

Terraforming of Mars The terraforming of Mars or the terraformation of Mars is a hypothetical procedure that would consist of a planetary engineering project or concurrent projects, with the goal of transforming Mars from a planet hostile to terrestrial life to o ...

Mars in popular culture

Mars in fiction Mars, the fourth planet from the Sun, has appeared as a setting in works of fiction since at least the mid-1600s. It became the most popular celestial object in fiction in the late 1800s as the Moon was evidently lifeless. At the time, the pr ...

** John Carter of Mars ** Martians *** '' Mars Attacks!'' *** '' The War of the Worlds'' ** Films set on Mars

References

NASA World Wind NASA WorldWind is an open-source (released under the NOSA license and the Apache 2.0 license) virtual globe. According to the website (https://worldwind.arc.nasa.gov/), "WorldWind is an open source virtual globe API. WorldWind allow ...

Celestia Celestia is a real-time 3D astronomy software program that was created in 2001 by Chris Laurel. The program allows users to virtually travel through our universe and explore real objects that have been catalogued. Celestia also doubles as a pl ...

, and other applications Images
Mars images
by NASA's Planetary Photojournal
Mars images
by NASA's Mars Exploration Program
Mars images
by Malin Space Science Systems
HiRISE image catalog
by the University of Arizona Videos
Rotating color globe of Mars
by the National Oceanic and Atmospheric Administration
Rotating geological globe of Mars
by the United States Geological Survey * by The Science Channel (2012, 4:31)
Flight Into Mariner Valley
by Arizona State University Cartographic resources
Mars nomenclature
an
quadrangle maps with feature names
by the United States Geological Survey
Geological map of Mars
by the United States Geological Survey
Viking orbiter photomap
by Eötvös Loránd University
Mars Global Surveyor topographical map
by Eötvös Loránd University {{Outline footer * Mars Mars