Astronomy Basics

Planet Data Reference

  
 
  Mercury
Image of Mercury: NASA/JPL/Northwestern University		 Venus
Image of Venus: L. Esposito (University of Colorado, Boulder), and NASA		 Earth
Image of Earth: NASA (Apollo 17)		 Mars
Image of Mars: NASA		 Jupiter
Image of Jupiter: NASA/JPL/University of Arizona		 Saturn
Image of Saturn: NASA/JPL/Space Science Institute		 Uranus
Image of Uranus: NASA (Voyager 2)		 Neptune
Image of Neptune: NASA (Voyager 2)		 Pluto
Image of Pluto: NASA (Hubble)
Mass 1024kg 0.3302 4.8685 5.974 0.6419 1,898.6 468.46 86.83 102.43 0.0125
Volume 1010km3 6.083 92.843 108.321 16.318 143,128 82,713 6,833 6,254 0.0125
Mean Radius km 2,440 6,052 6,371 3,370 69,911 58,232 25,362 24,624 0.715
Surface gravity (g) ms-2 3.7 8.9 9.8 3.7 24.8 10.4 8.9 11.2 0.58
Number of Moons 0 0 1 2 63 33 26 13 1
Distance from Sun
(semi-major axis) 106km		 57.8 108.2 149.6 227.9 778.6 1,443.5 2,872.5 4,495.1 5,869.7
Min distance from sun
(perihelion) 106km		 46.0 107.5 147.1 206.6 740.5 1,352.6 2,741.3 4,444.5 4,435.0
Max distance from sun
(aphelion) 106km		 69.8 108.9 152.1 249.2 816.6 1,514.5 3003.6 4,545.7 7,304.3
Eccentricity 0.21 0.0067 0.017 0.094 0.049 0.057 0.046 0.011 0.24
Inclination of rotation to orbit 0.01° 177.36° 23.45° 25.19° 3.13° 26.73° 97.77° 28.32° 122.55°
Length of "Day"
(Rotation period) hrs		 4,223 2,802 24.0 24.7 9.9 10.7 17.2 16.1 153.3
Length of "Year"
(Orbital period) days		 87.969 224.701 365.256 686.980 4,332.589 10,759.22 30,685.4 60,189 90,465
Discoverer Unknown Unknown Erm... Unknown Unknown Unknown William Herschel
(1781)		 Johann Galle
(1846)		 Clyde Tombaugh
(1930)
Atmosphere Pressure bar 10-15 92 1 0.006 >>1000 >>1000 >>1000 >>1000 10-6
Atmosphere Composition O2, Na, H2 CO2, N2 N22 CO2, N2 H2, He H2, He H2, He H2, He CH4, N2
Average Temperature °C 167 464 15 -63 -108 -139 -197 -201 -223


Source: National Space Science Data Center/NASA