Hello, I am new to this forum and this is my first thread! :) I would like to know how I can compute the Cartestian Coordinates (x,y,z) of the Moon, with the Earth at the origin during the eclipse of August 11 1999 at the time of the greatest eclipse point (http://en.wikipedia.org/wiki/Solar_eclipse_of_August_11,_1999). I'm trying to create a program that can predict Solar eclipses. I have chosen the (x,y) plane to be the ecliptic plane (Earth-Sun plane), so the z coordinate of the Moon would have to be almost 0. I say almost 0 because, when I say coordinates, I'm referring to the coordinates of the center of the Moon ... and the center of the Moon, the center of the Earth and the center of the Sun weren't colinear during that eclipse (honestly I doubt there was an eclipse in which they were perfectly colinear). My program only works with points, not whole objects (not yet at least). Thank you!