Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Planetary Positions according to JPL Data

  1. Jul 30, 2010 #1
    Attached is a Excel program given a Date it will susposedly give the Keplarian data for each of the Planets. It does not work. The Data is given from Nasa JPL:

    http://ssd.jpl.nasa.gov/txt/p_elem_t2.txt

    Julian Date and J2000 are calculated. J2000 or just J is plugged into the JPL data:

    a-Semi-Major Axis
    e-Eccentricity
    i-inclination
    ML-Mean Longitude
    LP-Longitude of the Perihelion
    N-Longitude of the Ascending Node

    Calculated from the above are:

    MA-Mean Anomaly
    EA-Eccentric Anomaly
    w-Argument of the Perihelion
    r-Planet Radius from the Sun
    v-True Anomaly
    Equ-Equinox-On Mar 21 looking thru the Sun the angle it makes with the projected Perihelion

    The True Anomaly gives the approximate answer for all dates but my logic is flawed if you use the equation:

    vActual=Equ+N+w+v

    I have worked a long time on this. Any input would be much appreciated!!!
     

    Attached Files:

    Last edited: Jul 30, 2010
  2. jcsd
  3. Jul 30, 2010 #2
    I gave you the wrong file. The other is too big for the Physics Forum. The point I was trying to make is that from the angle looking thru the sun at the Vernal Equinox or 3-31 added together vActual=Equ+N+w+v yields a somewhat correct answer not taking into account of the inclination, i.
     
  4. Jul 31, 2010 #3
    Here is the file meant to show.
     

    Attached Files:

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook