Here’s a good question a reader asked—“Why are you writing about the South Node and the Moon together?” And I replied: I’m doing this because they mutually reinforce each other and tell more of the story of the heart.
Yes, they each are different—dare I say “slightly?”—in that the Moon describes your obvious emotional and nurturing style in this life and how you relate to all things “maternal” including your Mother. However, the Moon's Nodes—are the Nodes of the Moon! And the South Node specifically holds the emotional memory of the Soul, so the story goes back further in time. It speaks of the emotional memory (not linear or left-brain memory) that is carried over from life to life. I believe this memory is sometimes called "skandas" in Hinduism, or you could think of it as something embedded in your DNA.
So your Moon is more specific to this life and what you are conscious of, whereas the South Node of the Moon is more of the “unconscious emotional memory.” I find that the overlapping and synthesizing of the two is fascinating…have you considered how your Moon sign and South Node sign reflect something of your conscious and unconscious patterns?
Let's say your South Node is in Scorpio, ruled by Pluto, and your Moon is in Aries ruled by Mars. The ancient story embedded in your psyche may be deeply Plutonian, powerful, and perhaps tragic. And so, in this life your Soul chose to be born with a Mars ruled Aries Moon-- maybe your Soul knew in some mysterious way that now you needed to "survive, to have courage, to start fresh, and to be enthusiastic" rather than brooding.....sounds like a description of a life affirming Aries Moon to me. Maybe that Aries Moon person is somewhat irritable, impulsive, and independent--it might just be that the South Node in Pluto ruled Scorpio reflected a heavy karmic maternal inheritance.
So, it's similar to when Sun sign astrologers say: look at your Rising Sign as well as your Sun sign in reading about yourself because each has a message here--and I would add, that when you are looking at your Moon, look at your South Node sign as well...read both.