Register to reply

Need help finding exact time of planet aspects with Jean Meeus library

by orbit123
Tags: aspects, exact, jean, planet, time
Share this thread:
Jul11-14, 09:50 AM
P: 1
I am using the C library that comes with the book Astronomical Algorithms by Jean Meeus

This book and C library has a calculation for two planets Conjunction and Opposition but no other planet aspects. Does anyone know a method to find when two planets are a fixed degree apart such as 90 degrees, 120 degrees or any other degree?

The problem I have run into is that geocentric planets move through a retrograde and direct cycle. As an outer planet approaches the transition from retrograde to direct it is almost stationary at which time I can not calculate any accurate degree of separation. So I need a proven method to calculate the date-time of exact angular separate even when two planets are almost stationary.

Any advice would be appreciated.

Phys.Org News Partner Astronomy news on
Chandra X-ray Observatory finds planet that makes star act deceptively old
Astronomers release most detailed catalogue ever made of the visible Milky Way
Planets with oddball orbits like Mercury could host life
Greg Bernhardt
Jul14-14, 11:41 PM
Greg Bernhardt's Avatar
P: 9,700
I'm sorry you are not generating any responses at the moment. Is there any additional information you can share with us? Any new findings?
Jul15-14, 04:18 PM
P: 627
I think you're looking for a "Fundamental Solar System ephemeris".
I have never used such a thing, but there seems to be something useful at this site:

Aug5-14, 08:00 AM
tfr000's Avatar
P: 127
Need help finding exact time of planet aspects with Jean Meeus library

The only way to do this exactly is to run a full-blown ephemeris of the Solar System and interpolate. Meeus gives you some handy formulae to approximate a number of interesting configurations, but these are indeed approximations boiled down from the full ephemera.

Register to reply

Related Discussions
Mechanics of Solid Materials by Jean Lemaitre and Jean-Louis Chaboche Science & Math Textbooks 0
Finding the exact value of sec^2x Precalculus Mathematics Homework 9
Finding g on unknown planet given only total time and a random height Introductory Physics Homework 3
Finding the Density of a Planet using Time Introductory Physics Homework 5