cseligman.com Personal website of Courtney Seligman, Professor of Astronomy / Author About Professor Seligman / About His Novels      Help / Toolbar / Site Map / Links / Google Search / Contact Professor Seligman

Online Astronomy eText: The Planets Planetary Data Table Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto Perihelion Distance (AUs) .307 .718 .983 1.382 4.950 9.040 18.324 29.709 29.646 Aphelion Distance (AUs) .467 .728 1.017 1.666 5.458 10.124 20.078 30.385 48.826 Semi-Major Axis (AUs) 0.387 0.723 1.000 1.524 5.204 9.582 19.201 30.047 39.236 Semi-Major Axis (AUs) 0.4 0.7 1 1.5 5 10 20 30 40 Orbital Eccentricity 0.207 0.007 0.017 0.093 0.05 0.056 0.05 0.01 0.25 Orbital Period 87.97 days 224.7 days 365.26 days 687 days 11.9 years 29.5 years 84 years 164.8 years 247.7 years Inclination (degrees) 7 3 0 2 1 2 1 2 17 Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto Mass (Earth = 1) .0553 .815 1 .107 317.8 95.2 14.5 17.1 .0021 Diameter (Earth = 1) .383 .949 1 .533 11.2 9.45 4.01 3.88 .187 Volume (Earth = 1) .0562 .857 1 .151 1321 764 63.1 57.7 .0066 Density (Earth = 1) .984 .95 1 .71 .24 .13 .23 .3 .32 Density (Water = 1) 5.43 5.24 5.52 3.9 1.3 .7 1.2 1.6 1.8 Gravity (Earth = 1) .38 .9 1 .38 2.5 1.1 .9 1.1 .06 Escape Velocity (Earth = 1) .38 .93 1 .45 5.3 3.2 1.9 2.1 .1 Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto Rotational Period 58.647 days -243 days 23 h 56 m 24 h 37 m 9 hr 50 min 10 hr 15 min -17 hours 16 hours -6.39 days Day 175.94 days -117 days 24 h 0 m 24 h 39 m 9 hr 50 min 10 hr 15 min -17 hours 16 hours -6.39 days Rotational Tilt (degrees) 0 177 (-3) 23.5 24 3 27 98 (-82) 29 118 (-62) Rotational Notes locked to Sun retrograde +.001s/d/100 y (at Equator) (at Equator) retrograde locked to moon Surface Temperatures (Fahrenheit degrees) +600 to +800 daytime, -300 nighttime +850 to +890 +40 to +90 day, a little less at night +80 to -210, -70 average -250 cloudtops, warmer below -300 at 1 bar depth, warmer below -350 clouds -370 clouds -370 perihelion, -410 aphelion Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto Atmosphere (Earth = 1) "none" 100 1 .01 Very Large Very Large Very Large Very Large "none" Composition of Atmosphere solar wind, impacts, outgassing 96% CO2, 4% nitrogen 80% nitrogen, 20% oxygen 95% CO2, 3% nitrogen 90% hydrogen, 10% helium 90% hydrogen, 10% helium 90% hydrogen, 10% helium 90% hydrogen, 10% helium temporary nitrogen, methane Magnetic Field (Earth = 1) .01 none 1 .001 14 .7 .7 .4 none? Internal Structure and Composition rocky mantle, large metal core rocky mantle, average metal core rocky mantle, average metal core rocky mantle, small metal core liquid hydrogen and helium liquid hydrogen and helium liquid hydrogen and helium, water water, liquid hydrogen and helium dirty ice, rock