This is the Web Edition of "A Trip Into Space", a Coimbra-based electronic book on space science. Both the texts and the photos are by courtesy of National Aeronautics and Space Administration.

A Trip Into Space Fact Sheets Earth Fact Sheet	Index
See also: Notes On The Fact Sheets, The Earth - New Zealand, The Earth - Central Afghanistan, Planet Earth - The Blue Marble

Earth Fact Sheet

Bulk parameters

Mass (1024 kg)                 5.9736
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)            5515      
Surface gravity (m/s2)          9.78      
Escape velocity (km/s)         11.186
GM (x 106 km3/s2)               0.3986      
Bond albedo                     0.385  
Visual geometric albedo         0.367
Visual magnitude V(1,0)        -3.86
Solar irradiance (W/m2)         1367.6    
Black-body temperature (K)       247.3    
Topographic range (km)            20
Moment of inertia (I/MR2)       0.3308
J2 (x 10-6)                    1082.63      

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    
Obliquity to orbit (deg)         23.45     

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

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
Average temperature:  288 K
Diurnal temperature range: 283 K to 293 K
Wind speeds: 0 to 100 m/s
Mean molecular weight: 28.97 g/mole 
Atmospheric composition (by volume, dry air): 
    Major      : 78.084% Nitrogen (N2), 20.946% Oxygen (O2), 
    Minor (ppm): Argon (Ar) - 9340; Carbon Dioxide (CO2) - 350
                 Neon (Ne) - 18.18; Helium (He) - 5.24; CH4 - 1.7
                 Krypton (Kr) - 1.14; Hydrogen (H2) - 0.55 
    Water is highly variable, typically makes up about 1%

Last Update: 2005-Nov-01