Mercury Trine Mars Synastry: When How One of You Talks and What Drives the Other Speak the Same Language

Every birth chart has a Mercury and a Mars, and they do different jobs. Mercury is how you think and talk: what you notice, how you explain, ask and joke, how quickly you pick things up, and the small daily trade of messages and questions. Mars is what drives you: your energy, your effort, your initiative, what you go after and how soon. In this contact, one person's Mercury is about 120° from the other person's Mars, a third of the way round the zodiac.

A trine usually joins two signs of the same element: fire with fire, earth with earth, air with air, water with water. (Usually, not always: a trine that starts near the edge of a sign can reach into the next element.) The signs a trine joins are four apart, so they usually differ in mode. (Modes are the three ways the signs move: cardinal signs start things, fixed signs keep them going, mutable signs adapt as they go.) That is the geometry. The reading built on it is likeness: the way one of you puts things and the way the other gets going tend to come from the same kind of temperament, whether that is quick, practical, curious or feeling.

So what one of you says is often something the other already wants to act on, and what the other does is often what the first would have suggested. There may be little to translate on either side.

This pairing can appear between friends, siblings, colleagues, neighbours, or a parent and their child as readily as between partners, and it is one contact among many in any two charts.

In this contact one of you brings Mercury and the other brings Mars, and the two of you are in the same element. Call them the Mercury person and the Mars person.

If you are the Mercury person, you are mostly just thinking aloud, explaining, asking, working out what to say. Around the Mars person your ideas may find willing hands. What you propose tends to be taken up in a way that fits how you put it, and you may find that you talk more freely when you can see something happening as a result.

If you are the Mars person, you are mostly just going at what you are going at: the job, the project, the next step. Around the Mercury person your effort often comes with a clear account of itself. They may describe the task in terms you recognise, or put the plan in an order you would have chosen. You may find it easy to start when the explanation arrives in your own register.

If the link also runs the other way, from the Mars person's Mercury to the Mercury person's Mars, each of you is both. Then each of you is, at different moments, the one who proposes and the one who sets about it.

Put simply, the Mercury person tends to say it and the Mars person tends to start it. In a trine both jobs run with little friction, because the saying and the starting come from the same element.

The Mercury person often gives the Mars person a plan in terms that suit: a first step named clearly, a reason that makes sense, an order for the day. The Mars person often gives the Mercury person a use for the ideas: something to try, a deadline that makes a decision, a reason to turn "could" into "did".

What each may want is modest and often already there. The Mercury person may want the idea answered with more than a quick start, a sentence of reaction before the work begins. The Mars person may want the plan to arrive in time to act on, and a decision to go with it. In a trine these wants may be met without either of you working at it.

Day to day it can show in jobs that are agreed and begun inside a single conversation, and in a few words that are enough to set two people off together.

These are sketches, not reports: illustrations of how the contact might show up across different kinds of pairs.

• Neighbours. On the pavement, one neighbour wonders aloud whether sharing a pressure washer between the two houses would beat hiring one each. The other has already checked the price at the nearest tool shop.
• Parent and child. A child explains an idea for a school science project at some length. The parent suggests a first small experiment to try on the kitchen table, and the child is fetching a jug before the explanation is over.
• Colleagues. One colleague outlines how the shared spreadsheet could be reorganised. The other says they will start with the first tab, and the outline is a working file by the afternoon.
• Siblings. Two siblings think about a joint present for a relative. One proposes pooling the money; the other sets up the page to collect it, and the message to the rest of the family is drafted between them.
• Friends. One friend says they have always wanted to learn the clarinet. The other finds a second-hand one for sale nearby and sends the listing, with the opening hours.

In each sketch what one person says and what the other does come from the same direction, and nobody has to try to line them up.

A trine usually joins two signs four apart, which share an element and belong to different modes. So the two of you tend to share an element and differ in how that element moves. In plain terms: fire is enthusiasm and action, earth is practical steadiness, air is talk and ideas, water is feeling.

Fire. Both are quick and direct. One may be the starter where the other is the sustainer. It might look like two cousins who decide to organise a five-a-side league for their street: one pitches the idea in a few lines, and the other has the first fixture list written before the pitch is finished.

Earth. Both prefer what is practical and exact. One may set out the numbers while the other turns them into an order of work. It might look like two colleagues going through a budget: one reads the figures aloud and the other is already placing the orders.

Air. Both enjoy ideas for their own sake. One may open a subject, the other follow it up. It might look like two siblings on the phone who decide, in half an hour, to build a small family website, and share out the pages as they talk.

Water. Both go by feeling, and the feeling is of a kind they recognise in each other. It might look like two friends who talk, in low voices, about a mutual friend who has seemed lonely, and agree that one of them will start a weekly supper.

Ease is most of what this contact gives, and it can have a quieter side that belongs to this pair of planets.

Because the saying and the starting suit each other, a plan can be settled before it has been tested. An idea that fits the temperaments of both is not always one that has been looked at from another side, and neither of you may think to ask.

Because the language is shared, a difficulty may go unnamed. Things can run smoothly enough that a worry stays unspoken, since talking about it seems unnecessary.

And two people from the same element may favour the same ways of going about things. They may both leave the same chore, or the same awkward topic, until later, which is harder to see from inside.

This is what this kind of ease can be like to live with: smooth, and sometimes quiet about what it passes over.

The older sources used here say nothing about a Mercury and a Mars a third of the circle apart. The only passages in them that name Mercury together with Mars are William Lilly's (*Christian Astrology*, 1647, Book III, p. 638) and James Wilson's (*A Complete Dictionary of Astrology*, 1819, p. 381). Both are about the opposition. Neither says anything about the trine or separates it from the sextile, so nothing from them is used here.

The distinction this page draws, that a trine reads as likeness because it usually joins signs of the same element, is based on the kinds of sign a trine usually joins. It is an editorial reading, not something the older books say about Mercury and Mars. The same goes for everything else on this page: who the Mercury person and the Mars person are, what each gives and may want, the element variations and the sketches, which are illustrations.

• A short exchange between you often turns into a plan, and the plan is often begun the same day.
• One of you may say what the other was about to suggest.
• One of you may notice that things get done between you without much fuss.
• A job explained once may seldom be explained again.
• Now and then a plan goes ahead so smoothly that neither of you is sure it was ever questioned.