Mass (kg)............................................3.3 x 10^23

Diameter (km)........................................4878

Mean density (kg/m^3) ...............................5420

Average distance from Sun (AU).......................0.387

Escape velocity (m/sec)..............................4300

Rotation period (length of day in Earth days)........58.65

Revolution period (length of year in Earth days).....87.97

Obliquity (tilt of axis in degrees)..................0

Orbit inclination (degrees)..........................7

Orbit eccentricity (deviation from circular).........0.206

Mean surface temperature (K).........................452

 Maximum surface temperature (K)......................700

Minimum surface temperature (K)......................100

Visual geometric albedo (reflectivity)...............0.12

Largest known surface feature........................Caloris Basin(1350 km diameter)

Atmospheric components...............................trace amounts of hydrogen and helium