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Mars Earth Ratio (Mars/Earth)
Mass (1024 kg) 0.6419 5.9736 0.107
Volume (1010 km3) 16.318 108.321 0.151
Equatorial radius (km) 3397 6378 0.533
Polar radius (km) 3375 6356 0.531
Volumetric mean radius (km) 3390 6371 0.532
Core radius (km) 1700 3485 0.488
Ellipticity 0.0065 0.0034 1.912
Mean density (kg/m3) 3933 5520 0.713
Surface gravity (m/s2) 3.69 9.78 0.377
Escape velocity (km/s) 5.03 11.19 0.450
GM (x 106 km3/s2) 0.04283 0.3986 0.107
Bond albedo 0.16 0.385 0.416
Visual geometric albedo 0.150 0.367 0.409
Visual magnitude V(1,0) -1.52 -3.86 -
Solar irradiance (W/m2) 595 1380 0.431
Black-body temperature (K) 216.6 247.3 0.875
Topographic range (km) 36 20 1.800
Moment of inertia (I/MR2) 0.366 0.3308 1.106
J2 (x 10-6) 1960.45 1082.63 1.811
Mars Earth Ratio (Mars/Earth)
Semimajor axis (106 km) 227.9 149.6 1.524
Sidereal orbit period (days) 686.980 365.256 1.881
Tropical orbit period (days) 686.930 365.242 1.881
Perihelion (106 km) 206.6 147.1 1.404
Aphelion (106 km) 249.2 152.1 1.638
Synodic period (days) 779.94 - -
Mean orbital velocity (km/s) 24.13 29.79 0.810
Orbit inclination (deg) 1.85 0.00 -
Orbit eccentricity 0.0934 0.0167 5.593
Sidereal rotation period (hrs) 24.6229 23.9345 1.029
Obliquity to orbit (deg) 25.19 23.45 1.074
Discoverer: Unknown
Discovery Date: Prehistoric
Apparent diameter from Earth
Maximum (seconds of arc) 25.7
Minimum (seconds of arc) 3.5
Distance from Earth
Minimum (106 km) 54.5
Maximum (106 km) 401.3
Apparent magnitude at opposition -2.0
Semimajor axis (AU) 1.52366231 Orbital eccentricity 0.09341233 Orbital inclination (deg) 1.85061 Longitude of ascending node (deg) 49.57854 Longitude of perihelion (deg) 336.04084 Mean Longitude (deg) 355.45332
Surface Pressure: ~6.1 mb (variable) [6.9 mb to 9 mb (Viking 1 Lander site)]
Surface Density: ~0.020 kg/m3
Scale height: 11.1 km
Average temperature: ~210 K
Diurnal temperature range: 184 K to 242 K (Viking 1 Lander site)
Wind speeds: 2-7 m/s (summer), 5-10 m/s (fall), 17-30 m/s (dust storm) (Viking Lander sites)
Mean molecular weight: 43.34 g/mole
Atmospheric composition (by volume):
Major : Carbon Dioxide (CO2) - 95.32% ; Nitrogen (N2) - 2.7%
Argon (Ar) - 1.6%; Oxygen (O2) - 0.13%; Carbon Monoxide (CO) - 0.08%
Minor (ppm): Water (H2O) - 210; Nitrogen Oxide (NO) - 100; Neon (Ne) - 2.5;
Hydrogen-Deuterium-Oxygen (HDO) - 0.85; Krypton (Kr) - 0.3;
Xenon (Xe) - 0.08
Phobos Deimos
Mean distance from Mars (km) 9377 23436
Sidereal orbit period (days) 0.31891 1.26244
Orbital inclination (deg) 1.08 1.79
Orbital eccentricity 0.0151 0.00033
Major axis radius (km) 13 8
Minor axis radius (km) 9 5
Mass (1015 kg) 10.8 1.8
Mean density (kg/m3) 1900 1750
Geometric albedo 0.06 0.07
Visual magnitude V(1,0) +11.8 +12.89
Notes on the factsheets
- definitions of parameters, units, notes on sub- and superscripts, etc.
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