Pluto Fact Sheet

[Pluto]

Pluto/Earth Comparison

Bulk parameters

   
   Pluto   		  
   Earth   		 Ratio
(Pluto/Earth)
Mass (1024 kg) 0.01303 5.9722 0.0022
Volume (1010 km3) 0.702 108.321 0.0065
Equatorial radius (km) 1188 6378.1 0.186
Polar radius (km) 1188 6356.8 0.187
Volumetric mean radius (km) 1188 6371.0 0.186
Ellipticity (Flattening) 0.0000 0.00335 0.0
Mean density (kg/m3) 1854 5513 0.336
Surface Gravity (mean) (m/s2) 0.62 9.82 0.063
Surface acceleration (eq.) (m/s2) 0.62 9.78 0.063
Surface acceleration (pole) (m/s2) 0.62 9.83 0.063
Escape velocity (km/s) 1.21 11.19 0.108
GM (x 106 km3/s2) 0.000870 0.39860 0.0022
Bond albedo 0.72 0.294 2.45
Geometric albedo 0.52 0.434 1.2
V-band magnitude V(1,0) -1.0 -3.99 -
Solar irradiance (W/m2) 0.873 1361.0 0.00064
Black-body temperature (K) 37.5 254.0 0.147
Number of natural satellites 5 1  
Planetary ring system No No  

Orbital parameters

   
   Pluto   		  
   Earth   		 Ratio
(Pluto/Earth)
Semimajor axis (106 km) 5869.656 149.598 39.236
Sidereal orbit period (days) 90,560 365.256 247.94
Tropical orbit period (days) Unknown 365.242 -
Perihelion (106 km) 4434.987 147.095 30.150
Aphelion (106 km) 7304.326 152.100 48.023
Synodic period (days) 366.73 - -
Mean orbital velocity (km/s) 4.64 29.78 0.156
Max. orbital velocity (km/s) 6.10 30.29 0.201
Min. orbital velocity (km/s) 3.71 29.29 0.127
Orbit inclination (deg) 17.16 0.000 -
Orbit eccentricity 0.2444 0.0167 14.635
Sidereal rotation period (hrs) -153.2928 23.9345 6.405
Length of day (hrs) 153.2820 24.0000 6.387
Obliquity to orbit (deg) 119.51 23.44 -
Inclination of equator (deg) 57.47 23.44 2.452

Pluto Observational Parameters

Discoverer:      Clyde Tombaugh
Discovery Date:  18 February 1930

Distance from Earth
        Minimum (106 km)         4284.7
        Maximum (106 km)         7528.0
Apparent diameter from Earth
        Maximum (seconds of arc)    0.11
        Minimum (seconds of arc)    0.06
Mean values at opposition from Earth
        Distance from Earth (106 km)       5756.78    
        Apparent diameter (seconds of arc)    0.08
        Apparent visual magnitude            15.1      
Maximum apparent visual magnitude            13.65

Pluto Mean Orbital Elements (J2000)

Semimajor axis (AU)                 39.48168677  
Orbital eccentricity                 0.24880766  
Orbital inclination (deg)           17.14175  
Longitude of ascending node (deg)  110.30347  
Longitude of perihelion (deg)      224.06676  
Mean longitude (deg)               238.92881

Positive Pole of Rotation

Right Ascension: 132.99
Declination    :   -6.16
Reference Date : 12:00 UT 1 Jan 2000 (JD 2451545.0)

Pluto Atmosphere

Surface Pressure: ~13 microbar
Surface temperature: 24 - 38 K (-247 - -233 C)
Scale height: ~18 km lower atmosphere, ~50 km above 30 km
Mean molecular weight: ~28 
Atmospheric composition:  99% Nitrogen (N2), 0.5% Methane (CH4), 0.05% Carbon Monoxide (CO), trace HCN, C2Hx hydrocarbons

Charon (P1)

Mean distance from Pluto (km)     19,596        
Sidereal orbit period (days)        6.3872        
Sidereal rotation period (days)     6.3872        
Orbital inclination to Pluto (deg)  0.00005       
Orbital eccentricity                0.0
Equatorial radius (km)              606          
Mass (1021 kg)                      1.586        
Mean density (kg/m3)               1700
Surface gravity (m/s2)              0.29
Escape velocity (km/s)              0.59  
Geometric Albedo                    0.42
Bond Albedo                         0.25
Apparent visual magnitude          16.8

Other Moons of Pluto

  Semi-Major
Axis (km)		 Orbital
Period (days)		 Rotation
Period (days)		 Mean Diameter
(km)		 Geometric
Albedo
Styx (P5) 42,413 20.16 3.24 10.5 0.65
Nix (P2) 48,690 24.85 1.83 48.4 x 33.8 x 31.4 0.56
Kerberos (P4) 57,750 32.17 5.31 19 x 10 x 9 0.56
Hydra (P3) 64,721 38.20 0.43 62.0 x 36.5 x 29.3 0.83

Orbital values are barycentric

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

Planetary Fact Table - metric units
Planetary Fact Table - U.S. units
Planetary Fact Table - Earth ratio

Pluto Home Page
Directory to other Planetary Fact Sheets
NASA
Author/Curator:
Dr. David R. Williams, dave.williams@nasa.gov
NSSDCA, Mail Code 690.1
NASA Goddard Space Flight Center
Greenbelt, MD 20771
+1-301-286-1258

NASA Official: Dave Williams, david.r.williams@nasa.gov
Last Updated: 11 January 2024, DRW