Profile:
Mass: 641,693,000,000,000 billion kg (0.107 x Earth)
Equatorial Diameter: 6,805
Polar Diameter: 6,755
Equatorial Circumference: 21,297 km
Known Moons: 2
Notable Moons: Phobos & Deimos
Orbit Distance: 227,943,824 km (1.38 x Earth's Distance to the Sun)
Orbit Period: 686.98 Earth days (1.88 Earth years)
Surface Temperature: -87 to -5 °C
Missions:
• MAVEN (2013)
NASA Mars Orbiter
• Mangalyaan (2013)
ISRO (India) Mars Orbiter
• NASA Mars Science Laboratory (2011)
NASA Mars Rover
• Phobos-Grunt (2011)
Attempted Russian Phobos Sample Return
• Yinghuo-1 (2011)
Attempted Chinese Mars Orbiter
• Phoenix (2007)
NASA Mars Scout Lander
• Mars Reconnaissance Orbiter (2005)
NASA Orbiter
Mars Exploration Rovers (2003)
Spirit and Opportunity, NASA Rovers to Mars
• Mars Express (2003)
ESA Mars Orbiter and Lander
• Mars Odyssey (2001)
NASA Orbiter Mission to Mars
• Mars Polar Lander (1999)
NASA attempted lander to Mars
• Deep Space 2 (1999)
NASA attempted penetrator mission to Mars
• Mars Climate Orbiter (1998)
NASA attempted orbiter to Mars
• Nozomi (Planet-B) (1998)
ISAS (Japan) orbiter to Mars
• Mars Global Surveyor (1996)
NASA Mars orbiter
• Mars Pathfinder (1996)
NASA lander and rover to Mars
• Mars 96 (1996)
Russian attempted mission to Mars
• Mars Observer (1992)
NASA attempted mission to Mars
​• Phobos (1988)
Soviet missions to Mars
• Viking (1975)
NASA orbiters/landers to Mars
• Mars 7 (1973)
Soviet attempted Mars lander
• Mars 6 (1973)
Soviet Mars lander
• Mars 5 (1973)
Soviet Mars orbiter
• Mars 4 (1973)
Soviet attempted Mars orbiter
• Mariner 9 (1971)
NASA Mars orbiter
• Mars 3 (1971)
Soviet Mars orbiter and lander
• Mars 2 (1971)
Soviet Mars orbiter and lander
• Mariner 7 (1969)
NASA Mars flyby
• Mariner 6 (1969)
NASA Mars flyby
• Mariner 4 (1964)
NASA Mars flyby
• Mars 1 (1962)
Soviet Mars flyby
Mars is a cold desert world. It is half the diameter of Earth and has the same amount of dry land. Like Earth, Mars has seasons, polar ice caps, volcanoes, canyons and weather, but its atmosphere is too thin for liquid water to exist for long on the surface. There are signs of ancient floods on Mars, but evidence for water now exists mainly in icy soil and thin clouds.
Mars Information
Latest News About Mars
Mars' Moons
Mars has two small moons: Phobos and Deimos. Phobos (fear) and Deimos (panic) were named for the mythological sons of Ares, the Greek counterpart of the Roman god, Mars. Both Phobos and Deimos were discovered in 1877 by American astronomer Asaph Hall. The moons appear to have surface materials similar to many asteroids in the outer asteroid belt, which leads most scientists to believe that Phobos and Deimos are captured asteroids.
To learn more about Mars' moons, click the button below!
NASA's Curiosity Mars rover recorded this sequence of views of the sun setting at the close of the mission's 956th Martian day, or sol (April 15, 2015), from the rover's location in Gale Crater.USA. Image Credit & Copyright: NASA/JPL-Caltech/MSSS/Texas A&M Univ.
NASA's Curiosity Mars rover used its Navigation Camera (Navcam) to capture this scene toward the west just after completing a drive that took the mission's total driving distance past 10 kilometers (6.214 miles).
Image Credit & Copyright: NASA/JPL-Caltech
10 Need-to-Know Things About Mars
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If the sun were as tall as a typical front door, Earth would be the size of a nickel, and Mars would be about as big as an aspirin tablet.
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Mars orbits our sun, a star. Mars is the fourth planet from the sun at a distance of about 228 million km (142 million miles) or 1.52 AU.
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One day on Mars takes a little over 24 hours (the time it takes for Mars to rotate once). Mars makes a complete orbit around the sun in 687 Earth days.
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Mars is a rocky planet, also known as a terrestrial planet. Mars' solid surface has been altered by volcanoes, impacts, crustal movement, and atmospheric effects such as dust storms.
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Mars has a thin atmosphere made up mostly of carbon dioxide (CO2), nitrogen (N2) and argon (Ar).
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Mars has two moons named Phobos and Deimos.
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There are no rings around Mars.
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More than 40 spacecraft have been launched for Mars. The first true Mars mission success was Mariner 4 in 1965.
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At this time in the planet's history, Mars' surface cannot support life as we know it. A key science goal is determining Mars' past and future potential for life.
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Mars is known as the Red Planet because iron minerals in the Martian soil oxidize, or rust, causing the soil -- and the dusty atmosphere -- to look red.
Spirit acquired the first two images with the panoramic camera on the night of sol 585 (Aug. 26,2005). The far right image of Phobos, for comparison, was taken by the High Resolution Stereo Camera on Mars Express, a European Space Agency orbiter. The third image in this sequence was derived from the far right image by making it blurrier for comparison with the panoramic camera images to the left. Image Credit & Copyright: NASA/JPL/Cornell/Ames/Texas A&M/ESA
Research and Exploration
Two orbiters — NASA's Mars Reconnaissance Orbiter and ESA's Mars Express — are keeping Mars Odyssey company over the planet. In 2011, NASA's Mars Science Laboratory mission, with its rover named Mars Curiosity, began to investigate Martian rocks to determine the geologic processes that created them and find out more about the present and past habitability of Mars. Among its findings is the first meteorite on the surface of the red planet.
In September 2014, India’s Mars Orbiter Mission reached the red planet, making it the fourth nation to successfully enter orbit around Mars.
Robots aren’t the only ones looking to buy a ticket to Mars. A workshop group of government, academic, and industry scientists have found that a NASA-led manned mission to Mars should be possible by the 2030s.
To learn more about the missions that have studied Mars, click on the links under the "Missions" sidebar above.
Physical characteristics
The bright rust color Mars is known for is due to iron-rich minerals in its regolith — the loose dust and rock covering its surface. The soil of Earth is a kind of regolith, albeit one loaded with organic content. According to NASA, the iron minerals oxidize, or rust, causing the soil to look red.
The cold, thin atmosphere means liquid water currently cannot exist on the Martian surface for any length of time. This means that although this desert planet is just half the diameter of Earth, it has the same amount of dry land.
