The composite chart is created by taking the midpoint between pairs of each of two person’s natal planets (in this case the Sun and Mercury) and using them to create a third, new chart. The composite chart is not the same as synastry, which examines how one person impacts the other. Instead the composite chart represents the relationship as a whole giving insight into the dynamics upon which it, as a relationship, functions.
The Composite Sun represents the thrust of the relationship – its primary purpose and vitality. The composite Sun functions like a lighthouse beacon, keeping the relationship clear of the proverbial rocks. A relationship embodying the essence of its composite Sun will likely be experienced as spontaneous and free. However, when expression of the relationship’s purpose and/or vitality is hindered in some way, it can be a struggle to keep things going.
Composite Mercury symbolises the manner and method in which communication occurs in the relationship. It also describes the nature of the decisions that the parties take regarding their relationship. In natal charts, Mercury is meant to be in active service to the Sun, feeding it with all information necessary to fulfil its purpose. In the composite chart, Mercury does exactly the same.
Composite Mercury/Sun in conjunction, trine, and sextile aspects favours verbal communication in a relationship; expect similarity in thinking. This aspect also allows the partners to maintain a helpful detached attitude when discussing their relationship although this strength can quickly become a weakness when feelings and emotions not easily reduced to words are overlooked. When composite Mercury/Sun are in square or opposition, expect miscommunication (whether or not purposeful). The parties to the relationship may well feel as if they’re speaking at cross purposes; what is said by one is not what is heard by the other.
When composite Mercury/Sun is affected by transit, the connection between the purpose of the relationship and the communication feeding it undergoes change.
Current transiting Neptune/Saturn square – (active November 2015 – September 2016)
Saturn = reality; duty and responsibility, respecting boundaries, integrity, discipline, mastery, doing the ‘right’ thing.
Neptune = unreality: dissolution, delusion, deception, denial, and dreams.
With Saturn in square with Neptune, there is no easy way to bridge the gap between dreams and reality; at times it may become impossible to tell the difference. The primary question with transiting Saturn square Neptune is exactly what is ‘real’.
In regards to relationships, it won’t be easy to answer this question because most folks never seriously question the purpose of their relationship much less whether that purpose is being fulfilled. The composite Sun should help in this regard because it symbolises the relationship’s purpose but this won’t be easy to access when the communication feeding the understanding/realisation of that purpose is (at best) murky.
Both Saturn and Neptune are in mutable signs at the moment and hence the foundation upon which that communication is built during this transit is even shakier that it otherwise might be. However, if those with composite Mercury/Sun effected by this transit can avoid getting caught up in typical Neptunian past-times like escape (into computer games, TV, or whatever), alcohol, drugs, and/or other forms of denial, then Saturn can provide them the focus and stamina to get their relationship even more creatively back on track.