Planetary Orbital Elements

Planetary Mean Orbits (J2000) (epoch = J2000 = 2000 January 1.5) (see the table of rates below)

Planet (mean) a AU e   i deg Omega deg ~omega deg L deg Mercury 0.38709893 0.20563069 7.00487 48.33167 77.45645 252.25084 Venus 0.72333199 0.00677323 3.39471 76.68069 131.53298 181.97973 Earth 1.00000011 0.01671022 0.00005 -11.26064 102.94719 100.46435 Mars 1.52366231 0.09341233 1.85061 49.57854 336.04084 355.45332 Jupiter 5.20336301 0.04839266 1.30530 100.55615 14.75385 34.40438 Saturn 9.53707032 0.05415060 2.48446 113.71504 92.43194 49.94432 Uranus 19.19126393 0.04716771 0.76986 74.22988 170.96424 313.23218 Neptune 30.06896348 0.00858587 1.76917 131.72169 44.97135 304.88003 Pluto 39.48168677 0.24880766 17.14175 110.30347 224.06676 238.92881

Planetary Orbital Element Centennial Rates (for the mean elements given above)

Planet (rate) a AU/Cy e /Cy i "/Cy Omega "/Cy ~omega "/Cy L "/Cy Mercury 0.00000066 0.00002527 -23.51 -446.30 573.57 538101628.29 Venus 0.00000092 -0.00004938 -2.86 -996.89 -108.80 210664136.06 Earth -0.00000005 -0.00003804 -46.94 -18228.25 1198.28 129597740.63 Mars -0.00007221 0.00011902 -25.47 -1020.19 1560.78 68905103.78 Jupiter 0.00060737 -0.00012880 -4.15 1217.17 839.93 10925078.35 Saturn -0.00301530 -0.00036762 6.11 -1591.05 -1948.89 4401052.95 Uranus 0.00152025 -0.00019150 -2.09 -1681.40 1312.56 1542547.79 Neptune -0.00125196 0.0000251 -3.64 -151.25 -844.43 786449.21 Pluto -0.00076912 0.00006465 11.07 -37.33 -132.25 522747.90

Legend:

  "     arcseconds
  Cy    Julian century
  a     semi-major axis
  e     eccentricity
  i     inclination
 Omega  longitude of the ascending node
~omega  longitude of perihelion
  L     mean longitude

This table contains mean orbit solutions from a 250 yr. least squares fit of the DE 200 planetary ephemeris to a Keplerian orbit where each element is allowed to vary linearly with time. This solution fits the terrestrial planet orbits to ~25" or better, but achieves only ~600" for Saturn. Elements are referenced to mean ecliptic and equinox of J2000 at the J2000 epoch (2451545.0 JD).

Reference: Explanatory Supplement to the Astronomical Almanac. 1992. K. P. Seidelmann, Ed., p.316 (Table 5.8.1), University Science Books, Mill Valley, California.

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