Moon Fact Sheet

[Global view of Moon]

Moon/Earth Comparison

Bulk parameters

                                   Moon         Earth      Ratio (Moon/Earth)
Mass (1024 kg)                    0.07349       5.9736     0.0123    
Volume (1010 km3)                 2.1973      108.321      0.0203
Equatorial radius (km)	           1738          6378      0.2725      
Polar radius (km)                  1735          6356      0.2730
Volumetric mean radius (km)        1737.5        6371      0.2727
Ellipticity                       0.002         0.0034     0.588    
Mean density (kg/m3)               3340          5520      0.6051      
Surface gravity (m/s2)            1.62          9.78       0.166    
Escape velocity (km/s)            2.38         11.2        0.213    
GM (x 106 km3/s2)                 0.0049        0.3986     0.0123 
Bond albedo                       0.067         0.385      0.174
Visual geometric albedo           0.12          0.367      0.327    
Visual magnitude V(1,0)          +0.21         -3.86          -
Solar irradiance (W/m2)            1380          1380      1.000      
Black-body temperature (K)          274.5         247.3    1.110      
Topographic range (km)               16            20      0.800      
Moment of inertia (I/MR2)         0.394         0.3308     1.191

Orbital parameters (for orbit about the Earth)

                                    Moon         
Semimajor axis (106 km)             0.3844                 
Perigee (106 km)                    0.3633
Apogee (106 km)                     0.4055
Revolution period (days)           27.322              
Synodic period (days)              29.53               
Mean orbital velocity (km/s)        1.023                  
Orbit inclination (deg)             5.145                    
Orbit eccentricity                  0.0549              
Sidereal rotation period (hrs)    655.728                
Equatorial inclination (deg)        6.68                   
Recession rate from Earth (cm/yr)   3.8

For information on the Earth, see the Earth Fact Sheet.

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.

* Moon 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, (301) 286-1258
NSSDC, Mail Code 633, NASA/Goddard Space Flight Center, Greenbelt, MD 20771
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NASA Official: J. H. King, king@nssdca.gsfc.nasa.gov
Last Updated: 19 June 1997, DRW