Jupiter Fact Sheet


[Montage of Jupiter and the Galilean Satellites]

Jupiter/Earth Comparison


Bulk parameters

                                   Jupiter      Earth   Ratio (Jupiter/Earth)
Mass (1024 kg)                      1,898.6     5.9736      317.83 
Volume (1010 km3)                 143,128     108.321      1321.33
Radius (1 bar level) (km)
    Equatorial                     71,492       6,378        11.21     
    Polar                          66,854       6,356        10.52
Volumetric mean radius (km)        69,911       6,371        10.97
Ellipticity                         0.0649      0.0034       19.09  
Mean density (kg/m3)                1,326       5,520         0.240 
Gravity (eq., 1 bar) (m/s2)        23.12        9.78          2.364 
Escape velocity (km/s)             59.5        11.19          5.32
GM (x 106 km3/s2)                 126.686       0.3986      317.8 
Bond albedo                         0.70        0.385         1.82
Visual geometric albedo             0.52        0.367         1.42  
Visual magnitude V(1,0)            -9.40       -3.86           -
Solar irradiance (W/m2)            51.       1380.            0.037
Black-body temperature (K)         90.6       247.3           0.366
Moment of inertia (I/MR2)           0.254       0.3308        0.768 
J2 (x 10-6)                        14,736    1082.63         13.611    

Orbital parameters

                                   Jupiter      Earth   Ratio (Jupiter/Earth)
Semimajor axis (106 km)             778.4       149.6         5.203   
Sidereal orbit period (days)      4,332.589     365.256      11.862   
Tropical orbit period (days)      4,330.595     365.242      11.857
Perihelion (106 km)                 740.6       147.1         5.035      
Aphelion (106 km)                   816.0       152.1         5.365
Synodic period (days)               398.88        -             -
Mean orbital velocity (km/s)         13.07       29.79        0.439   
Orbit inclination (deg)               1.305       0.00          -
Orbit eccentricity                    0.04839     0.0167      2.898
Sidereal rotation period (hours)      9.9250*    23.9345      0.415  
Obliquity to orbit (deg)              3.12       23.45        0.133 

* System III (1965.0) coordinates


Jupiter Observational Parameters

Discoverer:      Unknown
Discovery Date:  Prehistoric

Apparent diameter from Earth
        Maximum (seconds of arc)   59.0
        Minimum (seconds of arc)   29.8
Distance from Earth
        Minimum (106 km)          588.5
        Maximum (106 km)          968.1
Apparent magnitude at opposition   -2.7      

Jupiter Mean Orbital Elements (J2000)

Semimajor axis (AU)                  5.20336301  
Orbital eccentricity                 0.04839266   
Orbital inclination (deg)            1.30530  
Longitude of ascending node (deg)  100.55615   
Longitude of perihelion (deg)       14.75385   
Mean Longitude (deg)                34.40438  

Jovian Magnetosphere

Goddard Space Flight Center O4 Model
    Dipole field strength: 4.28 gauss-Rj3
    Dipole tilt to rotational axis: 9.6 degrees
    Longitude of tilt: 201.7 degrees
    Dipole offset (planet center to dipole center) distance: 0.131 Rj
    Latitude/Longitude of offset vector: -8.0 degrees/148.57 degrees

Note: All latitudes/longitudes are given in Jovian System III (1965.0) coordinates.
Rj denotes Jovian radii, 71,398 km


Jovian Atmosphere

Surface Pressure: >>100 bars  
Average temperature: ~129 K
Temperature at 1 bar: ~165 K
Density at 1 bar: ~0.16 kg/m3
Wind speeds
   Up to ~150 m/s (<30 degrees latitude)
   Up to  ~40 m/s (>30 degrees latitude)
Scale height: 27 km
Mean molecular weight: 2.22 g/mole
Atmospheric composition (uncertainty in parentheses)
    Major:       Molecular hydrogen (H2) - 89.8% (2.0%); Helium (He) - 10.2% (2.0%)
    Minor (ppm): Methane (CH4) - 3000 (1000); Ammonia (NH3) - 260 (40);
                 Hydrogen Deuteride (HD) - 28 (10); Ethane (C2H6) - 5.8 (1.5);
                 Water (H2O) - ~4 (varies with pressure)
    Aerosols:    Ammonia ice, water ice, ammonia hydrosulfide

If no sub- or superscripts appear on this page - for example, if the "Mass" is given in units of "(1024 kg)" - you may want to check the notes on the sub- and superscripts.

* Notes on the factsheets - definitions of parameters, units, notes on sub- and superscripts, etc.


* Jovian Satellite Fact Sheet
* Jovian Rings Fact Sheet
* Jupiter Home Page
* Directory to other Planetary Fact Sheets
* NSSDC Planetary Home Page
Questions and comments about this page should be addressed to:
Dr. David R. Williams, dwilliam@nssdc.gsfc.nasa.gov, +1-301-286-1258
NSSDC, Mail Code 633, NASA/Goddard Space Flight Center, Greenbelt, MD 20771
or
Dr. Edwin V. Bell II, ed.bell@gsfc.nasa.gov, +1-301-286-1187
NSSDC, Mail Code 633, NASA/Goddard Space Flight Center, Greenbelt, MD 20771
[NSSDC logo]

NASA Official: J. H. King, joseph.h.king@gsfc.nasa.gov
Last Updated: 10 March 1999, EVB II