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Hydrology of Mars

Mars Astronomical symbol of Mars
OSIRIS Mars true color.jpg
Mars in true color imaged by the OSIRIS instrument on the Rosetta spacecraft during its February 2007 flyby
Designations
Pronunciation UK English: /mɑːz/
US English: Listeni/ˈmɑːrz/
Adjectives Martian
Orbital characteristics
Epoch J2000
Aphelion 1.6660 AU
249.2 Gm
Perihelion 1.3814 AU
206.7 Gm
1.523679 AU
227.9392 Gm
Eccentricity 0.0934
1.8808 Julian years
686.971 d
668.5991 sols
779.96 days
2.135 Julian years
Average orbital speed
24.077 km/s
19.373°
Inclination 1.850° to ecliptic
5.65° to Sun's equator
1.67° to invariable plane
49.558°
286.502°
Satellites 2
Physical characteristics
Mean radius
3,389.5±0.2 km
Equatorial radius

3,396.2±0.1 km

0.533 Earths
Polar radius

3,376.2±0.1 km

0.531 Earths
Flattening 0.00589±0.00015

144,798,500 km2

0.284 Earths
Volume

1.6318×1011 km3

0.151 Earths
Mass

6.4171×1023 kg

0.107 Earths
Mean density
3.9335±0.0004 g/cm³

3.711 m/s²

0.376 g
0.3662±0.0017
5.027 km/s
Sidereal rotation period

1.025957 d

24h 37m 22s
Equatorial rotation velocity
868.22 km/h (241.17 m/s)
25.19° to its orbital plane
North pole right ascension

21h 10m 44s

317.68143°
North pole declination
52.88650°
Albedo 0.170 (geometric)
0.25 (Bond)
Surface temp. min mean max
Kelvin 130 K 210 K 308 K
Celsius −143 °C −63 °C 35 °C
Fahrenheit −226 °F −82 °F 95 °F
+1.6 to −3.0
3.5–25.1″
Atmosphere
Surface pressure
0.636 (0.4–0.87) kPa
0.00628 atm
Composition by volume

3,396.2±0.1 km

3,376.2±0.1 km

144,798,500 km2

1.6318×1011 km3

6.4171×1023 kg

3.711 m/s²

1.025957 d

21h 10m 44s

Mars is the fourth planet from the Sun 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 prevalent on its surface gives it a reddish appearance. Mars is a terrestrial planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the valleys, deserts, and polar ice caps of Earth.

The rotational period and seasonal cycles of Mars are likewise similar to those of Earth, as is the tilt that produces the seasons. Mars is the site of Olympus Mons, the largest volcano and second-highest known mountain in the Solar System, and of Valles Marineris, one of the largest canyons in the Solar System. The smooth Borealis basin in the northern hemisphere covers 40% of the planet and may be a giant impact feature. Mars has two moons, Phobos and Deimos, which are small and irregularly shaped. These may be captured asteroids, similar to 5261 Eureka, a Mars trojan.


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Wikipedia

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