Neptune: Planet Profile

Mass (kg) 1.02 x 1026
Diameter (km) 49528
Mean density (kg/m3) 1640
Escape velocity (m/s) 23300
Average distance from Sun 30.07 AU (4,498,252,900 km)
Rotation period (length of day in Earth days) 0.67 (16.1 hours)
Revolution period (length of year in Earth days) 60,190 (164.8 Earth years)
Obliquity (tilt of axis degrees) 29.6
Orbit inclination (degrees) 1.77
Orbit eccentricity (deviation from circular) 0.009
Mean temperature (K) 48
Visual geometric albedo (reflectivity) 0.51
Atmospheric components 74% hydrogen,
25% helium,
1% methane (at depth)
Rings Rings are narrow, and contain
concentrations of particles
called ring arcs.