Pluto Fact Sheet

All this information came from a employee of NASA: David R Willams

Pluto/Earth Comparison

Bulk parameters

                                  Pluto          Earth      Ratio (Pluto/Earth)

Mass (1024 kg)                    0.0125         5.9736         0.0021

Volume (1010 km3)                 0.616        108.321          0.0057

Volumetric mean radius (km)        1137           6371          0.1785         

Mean density (kg/m3)               2050           5520          0.3714

Surface gravity (m/s2)            0.66           9.78           0.0675

Escape velocity (km/s)            1.1           11.19           0.0983

GM (x 106 km3/s2)                 0.00083        0.3986         0.0021  

Bond albedo                       0.145          0.385          0.377

Visual geometric albedo           0.3            0.367          0.817

Solar irradiance (W/m2)           0.9            1380           0.0007

Black-body temperature (K)       42.7          247.3            0.1653

Orbital parameters

                                  Pluto           Earth      Ratio (Pluto/Earth)

Semimajor axis (106 km)         5906.4           149.6           39.48

Sidereal orbit period (days)     90,465          365.256        247.68

Tropical orbit period (days)     90,588          365.242        248.02

Perihelion (106 km)             4445.8           147.1           30.22        

Aphelion (106 km)               7381.2           152.1           48.53

Synodic period (days)            366.73             -              -

Mean orbital velocity (km/s)       4.75           29.79           0.1594

Orbit inclination (deg)           17.14            0.00            -

Orbit eccentricity                 0.2488          0.0167        14.898

Sidereal rotation period (hrs)   153.2928         23.9345         6.4047

Obliquity to orbit (deg)         122.46           23.45          (2.4563)

Pluto Observational Parameters

Discoverer:      Clyde Tombaugh

Discovery Date:  18 February 1930



Apparent diameter from Earth

        Maximum (seconds of arc)    0.11

        Minimum (seconds of arc)    0.06

Distance from Earth

        Minimum (106 km)         4293.7

        Maximum (106 km)         7533.3

Apparent magnitude at opposition   15.1

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



On 11 February 1999 at 11:22 UT, Pluto passes Neptune as the 

furthest planet from the Sun once again for the next 228 years.

Pluto Atmosphere

Surface Pressure: ~3 microbar

Average temperature: ~50 K

Scale height: ~60 km

Mean molecular weight: ~16-25 g/mole

Atmospheric composition:  Methane (CH4), Nitrogen (N2)

Charon

Mean distance from Pluto (km)    19,405        

Sidereal orbit period (days)       6.387        

Orbital inclination (deg)         96.56       

Orbital eccentricity               0.0

Equatorial radius (km)             586          

Mass (1021 kg)                     1.7         

Mean density (kg/m3)              1800

Surface gravity (m/s2)             0.21

Escape velocity (km/s)             0.58  

Albedo                             0.375