Ninety degrees and about a month
A square is a quarter of the circle with a seven degree orb, so the window is fourteen degrees wide. With Mars and Jupiter approaching at just under half a degree a day, the aspect holds for roughly a month.
There are two squares in each two and a quarter year cycle, one as Mars pulls ahead and one as Jupiter falls behind, which makes squares about twice as common as conjunctions between this pair. A Mars retrograde period inside the window can produce more than one exact hit, and a chart from such a stretch carries the pattern in a heavier form.
The two bodies fall in signs of the same mode and different elements. Shared urgency, mismatched material: that is the standard description of a square and it is a reasonable summary of what this pairing does.
The excess reading, examined
Mars supplies effort and the willingness to start a fight. Jupiter supplies scale and the assumption that there is room to grow. Set at ninety degrees, neither one moderates the other, and the friction is between two impulses that both want more.
The classical reading is overreach: too much undertaken, too much spent, arguments picked at a size out of proportion to the matter. The modern versions add restlessness and a low tolerance for being managed. All of that is recognisable in tight examples.
What deserves saying alongside it is that squares produce output. Charts that get a great deal done nearly always have squares doing the work, and this square pushes towards ambitious effort rather than towards caution. Whether the result reads as achievement or as wreckage depends on what else in the chart applies a brake, which is generally Saturn.
Dignity, house and the third body
Check which body is better placed. Jupiter in Sagittarius square Mars in Virgo is a square where the expansive side sets the agenda. Mars in Scorpio square Jupiter in Leo is one where the effort side does, and the person tends to describe a life of grinding rather than of grand plans.
House needs a birth time and does most of the specifying. From the third to the sixth, this is a story about work and daily conflict. From the fifth to the eighth, about risk and what gets staked. The generic description of the square is of limited use until it is anchored somewhere.
If a third body opposes either end, you have a T-square. The apex takes the pressure, and reading that apex will tell you more about the person than any single line in this article.
One more thing worth checking is the ruler of each house involved. A square from the third to the sixth whose rulers are also in aspect is a tightly wound version of the pattern. Where the rulers ignore each other, the square tends to stay a temperament rather than becoming a recurring situation.
How far to take it
This aspect is common to everyone born in the same month-long band, twice in each cycle. Anyone promising a specific destiny from it is going well beyond what the configuration supports.
The orb from the check above narrows it. A square inside a degree and a half is usually recognised at once when described. At six degrees it is a colouring, and it will lose to any tighter contact to the same Mars.
Retrograde motion needs no drama here. Jupiter is retrograde roughly four months a year and Mars two months in every two years, so either is an ordinary state. The only thing worth noting is that a Mars station near the square is what produces the repeated passes.
Questions people ask about this
Is Mars square Jupiter a difficult aspect?
It is a friction aspect, which is not the same as a bad one. It describes effort applied at a scale nothing in the pair checks, so it produces both overreach and a great deal of output. What decides the balance is usually whether Saturn is doing anything about it.
How often does it happen?
Twice in each two and a quarter year cycle between the pair, once on each side of the conjunction, and each pass holds for about a month at the seven degree orb. That makes squares roughly twice as common as conjunctions between Mars and Jupiter.
Can this aspect perfect more than once?
Yes. If Mars stations retrograde inside the window the two can square each other more than once over a span of months. A chart from such a period carries the pattern in a reinforced form, which is worth knowing before weighing it.
What signs are involved?
Signs of the same mode and different elements. Mars in Taurus square Jupiter puts Jupiter in Leo or Aquarius, all fixed signs. That shared mode is why the pair pulls in the same direction while disagreeing about the material.
Does it mean I take too many risks?
It describes a tendency for scale to outrun assessment, which often looks like risk taking. Whether it shows that way depends on the houses involved and on whether the chart has anything that habitually applies a brake.
What should I check after the orb?
The house pair, which needs a birth time, and any planet opposing either end. The second turns the square into a T-square, and the apex of a T-square is normally the single most descriptive point in a chart that has one.