Mass (kg)............................................ 1.29 x 10^22
Diameter ............................................ 1,430 mi.(2300 km.)
Mean density (kg/m^3) ............................... 2030
Escape velocity (m/sec).............................. 1100

Distance from the sun................................ Shortest-2,749,600,000 mi.(4,425,100,000 km.)
                                                      Greatest-4,582,700,000 mi.(7,375,100,000 km.)
					              Mean-3,666,200,000 mi.(5,900,100,000 km.) 
Rotation period (length of day in Earth days)........ 6.39
Revolution period (length of year in Earth years).... 247.7

Obliquity (tilt of axis in degrees).................. 122.5
Orbit inclination (degrees).......................... 17.15
Orbit eccentricity (deviation from circular)......... 0.248

Mean surface temperature(Farenheit).................. -387 to -369 (-233 C to -223 C)

Visual geometric albedo (reflectivity)............... about 0.5

Atmospheric components............................... perhaps 
                                                      methane and 
                                                      nitrogen 
Surface materials.................................... perhaps 
						      methane ice

Number of satellites................................. 1