How do I calculate planetary nodes?

Question

I would like to calculate a planets or bodies south and north node for astrological purposes.

Answer 1

As I understand the nodes are those points where the planetary path (that is inclined at an angle to ecliptic that means Sun's path as it appears from Earth) coincides with Sun's path. For Moon, these can be looked in the ephemeris available from every year being published by authorities like HMSO (Her majesty's stationery office).

For others, the six orbital elements need to be known for every planet. Inclination, position of perihelion are needed. Perihelion if it is changing like in the case of Mercury it gets more complex.

However, the orbital inclination has very marginal effect on Astrological factors that won't reveal as extent of each sign is 30 degrees and there is no chance of a planet straying beyond it. In the case of moon, where these nodes have been accorded the status (for Astrological purpose) of planets, others don't need this fine precision.