Expert: Jayendra Upadhye - 3/19/2006

Question
I am interested to know the formulae or algorithm or C code or vb code to evaluate the exact geocentric positions of sun ,moon ,mars, mercury , Venus, Jupiter, Saturn ,Uranus ,Neptune ,Pluto and two nodes of moon (dragon head and tail) Also I would like to know the technique to confirm whether the planetary motion is direct or retrogade.  

Answer
Hi,
Deshpande saheb, tumhi kharokarich kathin prashna vicharla ahe!
Mi C programming kele ahe, Vb pan!
Parantu never for the above things!
To my knowledge, there are sites on the www that cater to you needs well.
Fakta Rahu-ketu calculations asteel ki nahi dev jane, as westerners generally do not use rahu and ketu points to my knowledge.

I doubt any one would keep C or Vb code in open domain for such appliocation as it would be used by professional astrologers to make a killing!

Oops! just a casual search using the string "program for geocentric planetary positions" in yahoo has resulted in a great list of freeware sites!
here is the first one headed "Computing planetary positions "!
link:- http://www.stjarnhimlen.se/comp/ppcomp.html

That is a technical site, and accounts for perturbations of orbits due to gravitational influences of satellites over their parent planets and one planet over another! (especially pluto over neptune, where the two orbits are in a 3/2 resonance).

regarding rahu ketu...there is jyotir version 2.3..
link:- http://www.astroskop.se/en/software/

hope that suffices.
mind you the most accurate tables would be the ephimerids published by Nasa etc.

Jayen