Mars

Mars
	Mars in true color, as captured by the Hope orbiter. The Tharsis Montes can be seen at the center, with Olympus Mons just to the left and Valles Marineris at the right.
Designations
Adjectives	Martian
Symbol
Orbital characteristics
	Epoch J2000
Aphelion	249261000 km; (1.66621 AU)
Perihelion	206650000 km; (1.3814 AU)
Semi-major axis	227939366 km; (1.52368055 AU)
Eccentricity	0.0934
Orbital period (sidereal)	686.980 d; (1.88085 yr; 668.5991 sols)
Orbital period (synodic)	779.94 d; (2.1354 yr)
Average orbital speed	24.07 km/s
Mean anomaly	19.412°
Inclination	1.850° to ecliptic; 5.65° to Sun's equator; 1.63° to invariable plane;
Longitude of ascending node	49.57854°
Time of perihelion	2022-Jun-21
Argument of perihelion	286.5°
Satellites	2 (Phobos and Deimos)
Physical characteristics
Mean radius	3389.5±0.2 km
Equatorial radius	3396.2±0.1 km; (0.533 Earths)
Polar radius	3376.2±0.1 km; (0.531 Earths)
Flattening	0.00589±0.00015
Surface area	1.4437×108 km2; (0.284 Earths)
Volume	1.63118×1011 km3; (0.151 Earths)
Mass	6.4171×1023 kg; (0.107 Earths)
Mean density	3.9335 g/cm3
Surface gravity	3.72076 m/s2 (0.3794 g0)
Moment of inertia factor	0.3644±0.0005
Escape velocity	5.027 km/s; (18100 km/h)
Synodic rotation period	1.02749125 d; 24h 39m 36s
Sidereal rotation period	1.025957 d; 24h 37m 22.7s
Equatorial rotation velocity	241 m/s; (870 km/h)
Axial tilt	25.19° to its orbital plane
North pole right ascension	317.269°
North pole declination	54.432°
Albedo

Mars is the fourth planet from the Sun. The surface of Mars is orange-red because it is covered in iron(III) oxide dust, giving it the nickname "the Red Planet".^[22]^[23] Mars is among the brightest objects in Earth's sky, and its high-contrast albedo features have made it a common subject for telescope viewing. It is classified as a terrestrial planet and is the second smallest of the Solar System's planets with a diameter of 6,779 km (4,212 mi). In terms of orbital motion, a Martian solar day (sol) is equal to 24.5 hours, and a Martian solar year is equal to 1.88 Earth years (687 Earth days). Mars has two natural satellites that are small and irregular in shape: Phobos and Deimos.

Quick Facts Designations, Adjectives ...

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[lower-alpha 1]

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[2]

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[5]

[lower-alpha 2]

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Designations
Mars in true color,^{[lower-alpha 1]} as captured by the Hope orbiter. The Tharsis Montes can be seen at the center, with Olympus Mons just to the left and Valles Marineris at the right.
Adjectives	Martian
Symbol
Orbital characteristics^[1]
Epoch J2000
Aphelion	249261000 km (1.66621 AU)^[2]
Perihelion	206650000 km (1.3814 AU)^[2]
Semi-major axis	227939366 km (1.52368055 AU)^[3]
Eccentricity	0.0934^[2]
Orbital period (sidereal)	686.980 d (1.88085 yr; 668.5991 sols)^[2]
Orbital period (synodic)	779.94 d (2.1354 yr)^[3]
Average orbital speed	24.07 km/s^[2]
Mean anomaly	19.412°^[2]
Inclination	1.850° to ecliptic 5.65° to Sun's equator 1.63° to invariable plane^[4]
Longitude of ascending node	49.57854°^[2]
Time of perihelion	2022-Jun-21^[5]
Argument of perihelion	286.5°^[3]
Satellites	2 (Phobos and Deimos)
Physical characteristics
Mean radius	3389.5±0.2 km^{[lower-alpha 2]}^[6]
Equatorial radius	3396.2±0.1 km^{[lower-alpha 2]}^[6] (0.533 Earths)
Polar radius	3376.2±0.1 km^{[lower-alpha 2]}^[6] (0.531 Earths)
Flattening	0.00589±0.00015^[5]^[6]
Surface area	1.4437×10⁸ km²^[7] (0.284 Earths)
Volume	1.63118×10¹¹ km³^[8] (0.151 Earths)
Mass	6.4171×10²³ kg^[9] (0.107 Earths)
Mean density	3.9335 g/cm³^[8]
Surface gravity	3.72076 m/s² (0.3794 g₀)^[10]
Moment of inertia factor	0.3644±0.0005^[9]
Escape velocity	5.027 km/s (18100 km/h)^[11]
Synodic rotation period	1.02749125 d^[12] 24^h 39^m 36^s
Sidereal rotation period	1.025957 d 24^h 37^m 22.7^s^[8]
Equatorial rotation velocity	241 m/s (870 km/h)^[2]
Axial tilt	25.19° to its orbital plane^[2]
North pole right ascension	317.269°^[13]
North pole declination	54.432°^[13]
Albedo