(The second value represents the quantity as a fraction of the terrestrial value.)
Mass 641.9e21 kg 0.107 GM 42.83e3 km3/s2 0.107 Equatorial radius 3393 km 0.532 Polar radius 3373 km 0.531 Core radius 1700 km 0.488 Flattening 6.476e-3 1.912 Mean density 3933 kg/m3 0.713 Moment of inertia coefficient 0.366 1.106 J2 1.964e-3 1.811 Surface gravity 3.69 m/s2 0.377 Escape velocity 5.03 km/s 0.450 Topographic range 36 km 1.800
Semimajor axis 227.9e6 km 1.524 Sidereal period 686.980 d 1.881 Tropical period 686.930 d 1.881 Eccentricity 0.0934 5.593 Inclination 1.85 deg Synodic period 779.94 d Mean orbital velocity 24.13 km/s 0.810
Bond albedo 0.16 0.416 Visual geometric albedo 0.150 0.409 Visual magnitude V(1,0) -1.52 Solar irradiance 595 W/m2 0.431 Black-body temperature 216.6 K 0.875
Epoch 1994.0 North pole (RA and Dec) 317.64 deg / 52.86 deg Obliquity 25.19 deg Argument of prime meridian 166.20 deg at epoch Sidereal rotation rate 350.8919830 deg/d Sidereal rotation period 24.623 h
Surface pressure 6.9 to 9 mb (Viking Lander 1 site)
Surface Density ~0.020 kg/m3
Scale height 11.1 km
Mean molecular weight 43.34 g/mol
Average temperature ~210 K
Diurnal temperature range 184 to 242 K (Viking Lander 1 site)
Wind speeds 2 to 7 m/s (summer)
5 to 10 m/s (fall)
17 to 30 m/s (dust storm) (Viking Lander sites)
Composition (by volume):
Carbon Dioxide (CO2) 95.32%
Nitrogen (N2) 2.7%
Argon (Ar) 1.6%
Oxygen (O2) 0.13%
Carbon Monoxide (CO) 0.08%
Water (H2O) 210 ppm
Nitrogen Oxide (NO) 100 ppm
Neon (Ne) 2.5 ppm
(HDO) 0.85 ppm
Krypton (Kr) 0.3 ppm
Xenon (Xe) 0.08 ppm
Phobos Deimos
Mean distance from Mars 9377 km 23436 km
Sidereal orbit period 0.31891 d 1.26244 d
Orbital inclination 1.08 deg 1.79 deg
Orbital eccentricity 0.0151 0.00033
Major axis radius 13 km 8 km
Minor axis radius 9 km 5 km
Mass 10.8e15 kg 1.8e15 kg
Mean density 1900 kg/m3 1750 kg/m3
Geometric albedo 0.06 0.07
Visual magnitude V(1,0) +11.8 +12.89
Epoch JD 2449360.5 Mean distance 1.5236 AU Eccentricity 0.0933 Inclination 1.85 deg Longitude of ascending node 49.58 deg Longitude of perihelion 336.10 deg Mean longitude at epoch 290.69 deg