Earth Fact Sheet

Bulk parameters

Mass (10²⁴ kg)                 5.9726
Volume (10¹⁰ km³)             108.321   
Equatorial radius (km)	        6378.1    
Polar radius (km)               6356.8         
Volumetric mean radius (km)     6371.0
Core radius (km)                3485
Ellipticity (Flattening)        0.00335      
Mean density (kg/m³)            5514      
Surface gravity (m/s²)          9.798  
Surface acceleration (m/s²)     9.780        
Escape velocity (km/s)         11.186
GM (x 10⁶ km³/s²)               0.3986      
Bond albedo                     0.306  
Visual geometric albedo         0.367
Visual magnitude V(1,0)        -3.86
Solar irradiance (W/m²)         1367.6    
Black-body temperature (K)       254.3    
Topographic range (km)            20
Moment of inertia (I/MR²)       0.3308
J₂ (x 10^-6)                    1082.63      
Number of natural satellites       1          
Planetary ring system             No

Orbital parameters

Semimajor axis (10⁶ km)         149.60    
Sidereal orbit period (days)    365.256
Tropical orbit period (days)    365.242    
Perihelion (10⁶ km)             147.09        
Aphelion (10⁶ km)               152.10
Mean orbital velocity (km/s)     29.78        
Max. orbital velocity (km/s)     30.29
Min. orbital velocity (km/s)     29.29
Orbit inclination (deg)           0.000     
Orbit eccentricity                0.0167     
Sidereal rotation period (hrs)   23.9345    
Length of day (hrs)              24.0000
Obliquity to orbit (deg)         23.44

Earth Mean Orbital Elements (J2000)

Semimajor axis (AU)                  1.00000011  
Orbital eccentricity                 0.01671022   
Orbital inclination (deg)            0.00005  
Longitude of ascending node (deg)  -11.26064  
Longitude of perihelion (deg)      102.94719  
Mean Longitude (deg)               100.46435

North Pole of Rotation

Right Ascension:  0.00 - 0.641T
Declination    : 90.00 - 0.557T
Reference Date : 12:00 UT 1 Jan 2000 (JD 2451545.0)
T = Julian centuries from reference date

Terrestrial Magnetosphere

Dipole field strength: 0.3076 gauss-Re³
Latitude/Longitude of dipole N: 78.6 degrees N/70.1 degrees W
Dipole offset (planet center to dipole center) distance: 0.0725 Re
Latitude/Longitude of offset vector: 18.3 degrees N/147.8 degrees E

Note: Re denotes Earth radii, 6,378 km

Terrestrial Atmosphere

Surface pressure: 1014 mb
Surface density: 1.217 kg/m³
Scale height: 8.5 km
Total mass of atmosphere:  5.1 x 10¹⁸ kg
Total mass of hydrosphere:  1.4 x 10²¹ kg
Average temperature:  288 K (15 C)
Diurnal temperature range: 283 K to 293 K (10 to 20 C)
Wind speeds: 0 to 100 m/s
Mean molecular weight: 28.97 g/mole 
Atmospheric composition (by volume, dry air): 
    Major      : 78.08% Nitrogen (N₂), 20.95% Oxygen (O₂), 
    Minor (ppm): Argon (Ar) - 9340; Carbon Dioxide (CO₂) - 400
                 Neon (Ne) - 18.18; Helium (He) - 5.24; CH₄ - 1.7
                 Krypton (Kr) - 1.14; Hydrogen (H₂) - 0.55 
    Numbers do not add up to exactly 100% due to roundoff and uncertainty
    Water is highly variable, typically makes up about 1%