![]() Global view of Mars as seen by the Viking 1 orbiter in 1980, showing the Valles Marineris (center)
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Designations
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Pronunciation | ![]() |
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Adjective | Martian | |||||||||
Orbital characteristics
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Epoch J2000 | ||||||||||
Aphelion | 249,209,300 km 1.665 861 AU |
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Perihelion | 206,669,000 km 1.381 497 AU |
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Semi-major axis | 227,939,100 km 1.523 679 AU |
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Eccentricity | 0.093 315 | |||||||||
Orbital period | 686.971 days 1.8808 Julian years |
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Synodic period | 779.96 days 2.135 Julian years |
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Average orbital speed | 24.077 km/s | |||||||||
Mean anomaly | 19.3564° | |||||||||
Inclination | 1.850° to ecliptic 5.65° to Sun's equator 1.67° to invariable plane |
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Longitude of ascending node | 49.562° | |||||||||
Argument of perihelion | 286.537° | |||||||||
Satellites | 2 | |||||||||
Physical characteristics
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Equatorial radius | 3,396.2 ± 0.1 km 0.533 Earths |
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Polar radius | 3,376.2 ± 0.1 km 0.531 Earths |
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Flattening | 0.005 89 ± 0.000 15 | |||||||||
Surface area | 144,798,500 km2 0.284 Earths |
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Volume | 1.6318×10 0.151 Earths |
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Mass | 6.4185×10 0.107 Earths |
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Mean density | 3.9335 ± 0.0004 g/cm³ | |||||||||
Equatorial surface gravity | 3.711 m/s² 0.376 g |
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Escape velocity | 5.027 km/s | |||||||||
Sidereal rotation period |
1.025 957 day 24.622 9 h |
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Equatorial rotation velocity | 868.22 km/h (241.17 m/s) | |||||||||
Axial tilt | 25.19° | |||||||||
North pole right ascension | 21 h 10 min 44 s 317.681 43° |
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North pole declination | 52.886 50° | |||||||||
Albedo | 0.170 (geometric) 0.25 (Bond) |
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Surface temp. Kelvin Celsius |
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Apparent magnitude | +1.6 to −3.0 | |||||||||
Angular diameter | 3.5–25.1" | |||||||||
Atmosphere
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Surface pressure | 0.636 (0.4–0.87) kPa | |||||||||
Composition |
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