A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Sean C
Date: 2017 Mar 2, 23:08 -0800
I could be wrong here, but it seems to me that it can be done this way: If one subtracts the GHA of the body from the GHA of Aries, the RA of the body is obtained. If, when subtracting the RA of a particular hour from the RA of the following hour, a negative value is obtained, then the planet is in retrograde motion.