Satellites of Mars

                                    Phobos         Deimos
Semi-major axis* (km)                9378          23459
Sidereal orbit period (days)        0.31891        1.26244
Sidereal rotation period (days)     0.31891        1.26244
Orbital inclination (deg)            1.08           1.79
Orbital eccentricity                0.0151         0.0005
Major axis radius (km)                13.4            7.5
Median axis radius (km)               11.2            6.1
Minor axis radius (km)                 9.2            5.2
Mass (1015 kg)                       10.6            2.4
Mean density (kg/m3)                 1900           1750
Geometric albedo                      0.07           0.08
Visual magnitude V(1,0)             +11.8          +12.89
Apparent visual magnitude (V0)        11.3           12.40

*Mean orbital distance from the center of Mars.