The Planets

by Dominic Ford, Editor

Physical characteristics of the planets

Planet Mass (Earth masses)Radius (Earth radii)Mean distance from Sun (AU)Orbital period
Mercury 0.055 0.3829 0.387 88 days
Venus 0.815 0.950 0.723 225 days
Earth 1 1 1 365.2564 days
Mars 0.107 0.532 1.524 687 days
Jupiter 317.8 10.96 5.204 11.862 yrs
Saturn 95.152 9.4492 9.582 29.46 yrs
Uranus 14.54 4.01 19.23 84.3 yrs
Neptune 17.147 3.883 30.10 164.8 yrs

Orbital parameters of the planets

Below are osculating elements for the planets, given for epoch 1985 January 15.0 (i.e. unix time 474595200, Julian Day 2446080.5). Although these elements change over time due to perturbations of the orbits of the planets, they may be expected to give positions accurate to better than an arcminute for decades to come.

Planet Semimajor axis
(AU)
Mean motion
(deg/day)
EccentricityInclinationLongitude of
Ascending Node
Longitude of
perihelion
Mean longitude
at epoch
Mercury 0.387 099 4.092 34 0.205 629 7.005 9 48.350 77.434 209.664 3
Venus 0.723 326 1.602 15 0.006 772 3.394 7 76.723 131.70 67.141 3
Earth 1.000 018 0.985 582 0.016 773 0.002 0 354.9 102.972 114.712 2
Mars 1.523 638 0.524 061 0.093 298 1.850 9 49.604 335.942 11.873 3
Jupiter 5.202 48 0.083 099 1 0.048 058 1.304 7 100.467 15.662 300.342 9
Saturn 9.563 29 0.033 331 5 0.050 916 2.484 6 113.713 93.444 227.251 2
Uranus 19.293 7 0.011 630 3 0.047 285 0.774 6 74.056 177.048 249.248 8
Neptune 30.274 3 0.005 917 02 0.006 851 1.769 3 131.800 357.07 272.264 8

References

Green, R.M., Spherical Astronomy, CUP (Cambridge, 1985)

Ashburn

Latitude:
Longitude:
Timezone:

39.04°N
77.49°W
EDT

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