Saturn Fact Sheet

                                                                        All this information came from a NASA employee: David R willams 

Saturn/Earth Comparison

Bulk parameters

                                     Saturn      Earth   Ratio (Saturn/Earth)

Mass (1024 kg)                      568.46       5.9736       95.162 

Volume (1010 km3)                    82,713    108.321       763.59

Radius (1 bar level) (km)

    Equatorial                       60,268      6,378         9.449    

    Polar                            54,364      6,356         8.553

Volumetric mean radius (km)          58,232      6,371         9.140

Ellipticity                           0.0980     0.0034       28.82

Mean density (kg/m3)                    687      5,520         0.124

Gravity (eq., 1 bar) (m/s2)           8.96       9.78          0.916 

Escape velocity (km/s)               35.5       11.19          3.172

GM (x 106 km3/s2)                    37.931      0.3986       95.16

Bond albedo                           0.75       0.385         1.95

Visual geometric albedo               0.47       0.367         1.28

Visual magnitude V(1,0)              -8.88      -3.86            -

Solar irradiance (W/m2)              15.0        1,380.        0.011

Black-body temperature (K)           63.9      247.3           0.258

Moment of inertia (I/MR2)             0.210      0.3308        0.635

J2 (x 10-6)                      16,298.      1082.63         15.054

Orbital parameters

                                     Saturn      Earth   Ratio (Saturn/Earth)

Semimajor axis (106 km)            1,426.8       149.6         9.537

Sidereal orbit period (days)      10,759.22      365.256      29.457   

Tropical orbit period (days)      10,746.94      365.242      29.424

Perihelion (106 km)                1,347.6       147.1         9.161      

Aphelion (106 km)                  1,506.4       152.1         9.904

Synodic period (days)                378.09        -             -

Mean orbital velocity (km/s)           9.66       29.79        0.324

Orbit inclination (deg)                2.484       0.00          -

Orbit eccentricity                     0.05415     0.0167      3.243

Sidereal rotation period (hours)      10.500*     23.9345      0.439

Obliquity to orbit (deg)              26.73       23.45        1.140
* Saturnian System III coordinates 

Saturn Observational Parameters

Discoverer:      Unknown

Discovery Date:  Prehistoric



Apparent diameter from Earth

        Maximum (seconds of arc)   20.1

        Minimum (seconds of arc)   14.5

Distance from Earth

        Minimum (106 km)         1195.5

        Maximum (106 km)         1658.5

Apparent magnitude at opposition    0.7

Saturn Mean Orbital Elements (J2000)

Semimajor axis (AU)                  9.53707032  

Orbital eccentricity                 0.05415060   

Orbital inclination (deg)            2.48446   

Longitude of ascending node (deg)  113.71504   

Longitude of perihelion (deg)       92.43194   

Mean Longitude (deg)                49.94432

Saturnian Magnetosphere

    Dipole field strength: 0.210 gauss-Rs3

    Dipole tilt to rotational axis: < 1 degree

    Dipole offset (planet center to dipole center) distance: 0.04 to 0.05 Rs northward
Note: Saturn's magnetic field has significant quadrapole and octapole moments, making approximation of the central field as an offset dipole difficult.
Rs denotes Saturnian radii, 60,330 km

Saturnian Atmosphere

Surface Pressure: >>100 bars  

Average temperature: ~97 K

Temperature at 1 bar: ~134 K

Density at 1 bar: ~0.19 kg/m3

Wind speeds

   Up to ~400 m/s (<30 degrees latitude)

   Up to ~150 m/s (>30 degrees latitude)

Scale height: 59.5 km

Mean molecular weight: 2.07 g/mole

Atmospheric composition (uncertainty in parentheses)

    Major:       Molecular hydrogen (H2) - 96.3% (2.4%); Helium (He) - 3.25% (2.4%)

    Minor (ppm): Methane (CH4) - 4500 (2000); Ammonia (NH3) - 125 (75);

                 Hydrogen Deuteride (HD) - 110 (58); Ethane (C2H6) - 7 (1.5)

    Aerosols:    Ammonia ice, water ice, ammonia hydrosulfide