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Pluto Earth Ratio (Pluto/Earth) Mass (1024 kg) 0.0125 5.9736 0.0021 Volume (1010 km3) 0.715 108.321 0.0066 Equatorial radius (km) 1195 6378.1 0.187 Polar radius (km) 1195 6356.8 0.188 Volumetric mean radius (km) 1195 6371.0 0.188 Ellipticity (Flattening) 0.0000 0.00335 0.0 Mean density (kg/m3) 1750 5515 0.317 Surface gravity (m/s2) 0.58 9.80 0.059 Surface acceleration (m/s2) 0.58 9.78 0.059 Escape velocity (km/s) 1.2 11.19 0.107 GM (x 106 km3/s2) 0.00083 0.3986 0.0021 Bond albedo 0.4 - 0.6 0.306 1.3 - 2.0 Visual geometric albedo 0.5 - 0.7 0.367 1.4 - 1.9 Visual magnitude V(1,0) -1.0 -3.86 - Solar irradiance (W/m2) 0.89 1367.6 0.0007 Black-body temperature (K) 37.5 254.3 0.147 Number of natural satellites 3* 1 Planetary ring system No No * The two newly discovered moons of Pluto have been named Nix and Hydra.
Pluto Earth Ratio (Pluto/Earth) Semimajor axis (106 km) 5906.38 149.60 39.482 Sidereal orbit period (days) 90,465 365.256 247.68 Tropical orbit period (days) 90,588 365.242 248.02 Perihelion (106 km) 4436.82 147.09 30.164 Aphelion (106 km) 7375.93 152.10 48.494 Synodic period (days) 366.73 - - Mean orbital velocity (km/s) 4.72 29.78 0.158 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 0.2488 0.0167 14.899 Sidereal rotation period (hrs) -153.2928 23.9345 6.405 Length of day (hrs) 153.2820 24.0000 6.387 Obliquity to orbit (deg) 122.53 23.45 (2.451)
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) 5750.54
Apparent diameter (seconds of arc) 0.08
Apparent visual magnitude 15.1
Maximum apparent visual magnitude 13.65
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 (6:22 a.m. EST), Pluto passed Neptune as the furthest planet from the Sun once again and will remain so until 5 April 2231.
Right Ascension: 313.02 Declination : 9.09 Reference Date : 12:00 UT 1 Jan 2000 (JD 2451545.0)
Surface Pressure: ~3 microbar Average temperature: ~50 K (-223 C) Scale height: ~60 km Mean molecular weight: ~16-25 g/mole Atmospheric composition: Methane (CH4), Nitrogen (N2)
Mean distance from Pluto (km) 19,600 Sidereal orbit period (days) 6.38725 Sidereal rotation period (days) 6.38725 Orbital inclination to Pluto (deg) 0.0 Orbital eccentricity 0.0 Equatorial radius (km) 593 Mass (1021 kg) 1.62 Mean density (kg/m3) 1850 Surface gravity (m/s2) 0.31 Escape velocity (km/s) 0.60 Geometric albedo 0.38 Apparent visual magnitude 16.8
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
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