What Is a Conjunction?
Two bodies at the same degree of the zodiac — the one aspect that has no character of its own, because the character is entirely in which two bodies.
A conjunction is two bodies at the same ecliptic longitude, or close enough to it that an astrologer counts them as together. The exact angle is 0°, and the Zodiux chart counts a pair as conjunct while the gap between them is 7° or less — the same 7° its synastry engine on the compatibility tool uses. That is the definition, and it is the easy half. The hard half is that the conjunction is the only classical aspect with no meaning of its own. A trine is ease and a square is friction whichever bodies make them; a conjunction is whatever the two bodies are, fused. Venus conjunct Jupiter and Mars conjunct Saturn are the same angle and not remotely the same event, which is why generic conjunction advice is close to worthless and why the rest of this page is about reading the pair rather than the angle.
What counts as a conjunction
Take the two bodies' longitudes, subtract, and if the answer is over 180° subtract it from 360°. For a conjunction that leftover number is the whole story: the separation is the orb, because the exact angle is zero. A pair 2° apart is a 2° conjunction. A pair 9° apart is not a conjunction at all under the orb Zodiux uses, however much they look adjacent on the wheel.
Worked example. Venus at 4° Virgo sits at 154° of longitude, because Virgo begins at 150°. Mercury at 9° Virgo sits at 159°. The gap is 5°, so those two are conjunct with a 5° orb — real, but loose enough to sit near the bottom of any list. Put Mars at 27° Virgo instead, at 177°, and the gap from Venus is 23°. Same sign, same Virgo paragraph in every sun-sign book, no aspect whatsoever. The reverse case is just as common: the Sun at 28° Taurus (58°) and Mercury at 1° Gemini (61°) are 3° apart and tightly conjunct across a sign boundary, which is called an out-of-sign or dissociate conjunction.
Conjunctions are not rare and they are not universal. Sweeping the ten bodies weekly from 1980 to 2029 — 2,609 charts, all 45 pairs, a flat 7° orb — gives a mean of 2.28 conjunctions per chart, with 7.8% of charts carrying none at all. So having one is ordinary, having four is worth noticing, and having none is not a defect. What varies far more than the count is which pair it is.
A blend, not a relationship
Every other aspect leaves you two things you can still see separately, connected across a measurable distance. At 0° there is no distance, so there is nothing to connect. The two bodies do not cooperate or argue; they arrive as one function. A Mercury–Saturn conjunction does not hand out Mercury's quickness and Saturn's caution in turns — it produces a single voice that is fast and slow at once, curious and cautious in the same sentence, and no part of it can be traced back to one planet without the other.
That distinction is not pedantry. It changes three practical things about reading one.
What follows from the merge
- A conjunction is hard to notice from the inside. A square catches you in the act, because two aims visibly pull apart. A blend has no seam, so it presents as temperament — this is simply how I am — rather than as a dynamic. The thin version of this article called conjunctions volume knobs turned all the way up, and that is right, with one correction: a knob you have never seen turned down does not feel loud, it feels like the level.
- One transit hits both members at once. When a moving body reaches that degree it contacts the whole blend in a single pass, which is why conjunctions tend to be the placements people can date afterwards. Transits and retrogrades has the durations.
- Conjunctions chain. If a third body is within orb of either member, all three are bound into one lump. That is the mechanism behind a stellium, and it is why stelliums argue about the container: three bodies inside 7° of each other is a very different formation from three bodies scattered across one sign.
The most context-dependent aspect there is
The only generic statement that survives contact with real charts is that a conjunction is loud. Loud is a volume claim, not a direction claim, and every attempt to give the angle a mood collapses on the first counterexample. Venus conjunct Jupiter amplifies ease; Mars conjunct Saturn is a permanent negotiation nobody asked for. Same 0°, opposite experience.
The table is a summary of long-standing interpretive convention, not a set of predictions. Read the pair first and the orb second; nothing in it applies at 6°30' the way it applies at 30 arcminutes.
| Pair | What the blend tends to produce | What to watch |
|---|---|---|
| Sun + Moon | Identity and need in one place — the chart of someone born within about a day of a new moon, which is 3.8% of days. Nothing internal is pulling the other way. | No counterweight. The tradition notes that wanting and needing are hard to tell apart when they occupy the same degree. |
| Sun + Mercury | Thinking fused to identity: opinions arrive as self rather than as positions held. Read the orb hard here. | It is the least distinguishing conjunction in astrology. Mercury never gets more than about 28° from the Sun, so roughly one chart in five has this. |
| Venus + Jupiter | Warmth and expansion in one gesture. The old texts like this pairing more than any other and are describing something real. | Expansion with no brake. The same signal that makes generosity effortless makes excess effortless. |
| Mars + Saturn | Drive welded to restraint — effort as a default setting, and a high tolerance for grind. | It reads as friction that never resolves, because there is no gap for it to resolve across. The tradition frames the negotiation as permanent, not as a phase. |
| Mercury + Saturn | One voice that is simultaneously fast and slow, curious and cautious. Structure applied to thought. | Slowness read as incapacity. The tradition reads it as care, and the difference matters more here than the interpretation. |
| Moon + Saturn | Feeling and containment as one movement — reserve that is not absence. | Reserve mistaken for coldness by others, and sometimes by the chart's owner. |
| Venus + Mars | Wanting and pursuing become a single motion; appetite and taste stop being separable. | The blend cannot tell you whether something is valued or merely wanted. Nothing in the chart can. |
| Jupiter + Saturn | Expansion and limit in one signal — the pairing that produces plans with their own constraints built in. | It is a generational marker before it is a personal one. See the section below. |
Conjunctions to the Sun: combustion and cazimi
One conjunction is a special case in every traditional system, because the Sun is not just another body on the wheel. A planet within a few degrees of it is physically invisible from Earth — lost in the glare — and classical astrology built that observation straight into its judgements. The scheme has three zones, and the boundaries are visibility thresholds rather than measurements anyone has repeated since.
| Condition | Distance from the Sun | Traditional reading | Share of days Mercury qualifies |
|---|---|---|---|
| Under the beams | within about 15° | Dimmed. The planet's own agenda is hard to separate from the Sun's. | 47.4% |
| Combust | within about 8°30' | Burnt out of visibility — the weakest condition the scheme recognises. | 25.2% |
| Cazimi | within about 17 arcminutes | In the heart of the Sun. The strongest condition the scheme recognises, and the sharp reversal is the point. | Hours, six times a year |
| Conjunct, by the Zodiux orb | within 7° | No classical judgement — the chart reports the aspect and its orb, nothing more. | 20.5% |
Two things fall out of that table. The first is that combustion is not exotic: Mercury is under the beams on nearly half of all days, so a large fraction of everyone has a Sun–Mercury contact in some solar condition, and a rule that applies to half the population is a weak differentiator whatever it means. Venus is inside 7° of the Sun on 10.7% of days, and the Moon on 3.8%.
The second is that cazimi is brief rather than rare. Because a conjunction in longitude passes exactly through zero, every Sun–Mercury conjunction crosses the cazimi band on the way through. In 2026 the six crossings spend between 6.0 and 20.5 hours inside 17' — hours, not days, which is why cazimi is a moment in electional practice and almost never a birth-chart claim.
Which kind of Sun–Mercury conjunction it is depends on where Mercury is. Three of 2026's six fall with Mercury retrograde — those are inferior conjunctions, Mercury passing between Earth and the Sun — and three with Mercury direct, on the far side. Same 0° in longitude, opposite physical geometry. The retrograde ones sit near the midpoint of a Mercury retrograde period; the live retrograde tracker computes the current one from the same ephemeris.
Zodiux does not compute combustion or cazimi. The chart reports the conjunction and its orb and stops there, because the thresholds are traditional conventions that differ between authors and it would rather name one than silently pick one.
The conjunction you share with a generation
Tightness ranks aspects, but it does not make them personal, and conjunctions between slow bodies are where that breaks hardest. Two outer planets can hold a sub-degree orb for years, which makes such an aspect the tightest thing in a chart and the least distinguishing thing about its owner.
Measured against this site's own ephemeris: Uranus and Neptune sat inside 7° of each other without a break from 30 November 1989 to 29 January 1997 — 2,618 consecutive days, a little over seven years — and crossed exactly three times in 1993, on 2 February, 20 August and 25 October. Everyone born across those seven years carries that conjunction. It says something about a cohort; it says nothing that separates one member of the cohort from another.
Faster outer pairs are narrower but still shared, and they are usually split into two visits rather than one. Jupiter and Saturn met exactly on 21 December 2020, and were inside 7° for 119 days in the spring of that year and another 134 days from October into February 2021 — the gap in the middle is a retrograde pulling them back apart. They meet again on 31 October 2040, about every 19.9 years. Saturn and Pluto were exact on 13 January 2020. Saturn and Neptune were exact on 20 February 2026 after a run of 426 days inside 7°, from March 2025 to May 2026, with a short second visit that November.
The practical rule is simple: before you read a tight conjunction as a defining feature, check both bodies' speed. If both are slow, look at how many people born that decade share it, and read it as background rather than signature. The planets in astrology has the periods and reach of each body.
How to read a conjunction in your own chart
The chart does the arithmetic in your browser; it draws every aspect on the wheel and lists the tightest by orb. What it cannot do is decide which conjunctions deserve weight. This is the order that works.
Eight steps
- Find them. In the aspect list, the conjunctions are the pairs at 0°. Note the orb next to each — that number is the separation itself, not a distance from some other angle.
- Sort by orb and be honest about the tail. Under 1° is a structural feature of the chart. Between 1° and 3° is real. Past about 5° it is context, and at 6°–7° it is inside the orb only because the orb is a setting.
- Name both bodies in plain words before reading any interpretation. What does Mars do, in one clause? What does Saturn do? If you cannot write those two clauses, no conjunction paragraph will help.
- Write one sentence containing both, with no but in it. A conjunction that needs a but is being read as a relationship between two separate things, which is the one thing it is not.
- Check both speeds. If both bodies are Jupiter or slower, work out roughly how many people born that year share the pairing before treating it as personal.
- Check whether the Sun is one of them. If so, apply the solar frame above before anything else — a Sun conjunction is a statement about visibility first and about blending second.
- Check for a third body inside orb of either member. If one exists, you are not reading a conjunction any more; you are reading a cluster, and the interpretation belongs to the whole group.
- Note the sign, then stop. The blend takes on the sign it happens in, and that is the last input. Do not rank the conjunction against the rest of the chart — there is no scoreboard, and building one is how charts get read as verdicts.
One input limits the whole exercise. The Moon moves 12°–15° a day, so any conjunction involving it depends on the birth time being right. With no birth time Zodiux computes for local noon and says so, which can put the Moon's longitude out by up to about 7° — wider than the orb itself. Every planetary conjunction that does not involve the Moon survives an unknown birth time comfortably. See birth time and time zones for what a rounded time costs.
For the wider system — why only five angles are read, how orb conventions differ between astrologers, and why easy aspects are not the good ones — start at aspects in astrology. If the wheel itself is new, how to read a birth chart works through one in order.
Method. The definition and the arithmetic are checkable: a conjunction is the difference between two ecliptic longitudes, folded into the 0°–180° range, sitting within the orb of 0°. Every frequency figure on this page was measured for it rather than recalled, using the same Astronomy Engine build the site ships. The solar-zone shares and the Moon and Venus figures come from 18,263 daily samples spanning 1980 to 2029; the 2.28 conjunctions per chart and the 7.8% of charts with none come from a weekly sweep of the same span, 2,609 charts, all 45 pairs of the ten bodies at a flat 7° orb; the cazimi durations come from 2026 sampled every ten minutes; the conjunction dates come from sign-change scans on the longitude difference. The 7° orb and the compatibility engine's harmonic flag were read out of the shipped scripts, not described from memory.
Limits. The angles and the frequencies are astronomy; what a conjunction is said to mean is an interpretive convention with no experiment behind it, and this page reports that convention rather than endorsing it as fact. The combustion and cazimi thresholds vary between traditional authors — 8°30' and 17' are the figures most often quoted, not settled constants — and Zodiux does not compute either. The 7° orb is a setting, not a finding: widen it and pairs become conjunct that are not conjunct here, which is why any conjunction list is only as meaningful as the orb quoted beside it. Nothing here predicts events or describes anyone's health, finances or relationships, and no conjunction determines an outcome. Zodiux states its boundaries at what we do not claim.
Sources.
- Astronomy Engine — Open-source implementation of the VSOP87 and NOVAS algorithms. Supplies every position Zodiux reports, in the browser and at build time, as geocentric apparent ecliptic longitude corrected for light-time and aberration. Precision limits at how Zodiux computes your chart.
- Measurements made for this page — Solar-zone shares (Mercury within 15°, 8°30' and 7°; Venus within 7°; Moon within 7°) from 18,263 daily samples, 1980–2029. Conjunction counts from 2,609 weekly charts over the same span, all 45 pairs at a flat 7° orb. Cazimi durations from 2026 at ten-minute resolution. Conjunction dates from sign-change scans on the longitude difference.
- The shipped Zodiux scripts — The 7° conjunction orb appears in both the natal chart script and the synastry engine, applied flat to every pair. The synastry engine's classification of every conjunction as harmonious, and its seven-body list from the Sun to Saturn, were read from that code.
- Classical sources for the solar conditions — Under the beams, combust and cazimi come from the Hellenistic and medieval literature and travelled into English through the Renaissance textbooks. The thresholds given here — about 15°, about 8°30' and about 17 arcminutes — are the figures most commonly quoted; authors differ, and some set them per planet.
- Elongation constants — Mercury's maximum separation from the Sun in longitude measured 27.8° across 2020–2029 and Venus's 47.2°, consistent with the standard ~28° and ~48° figures. These caps are why Sun–Mercury and Sun–Venus conjunctions are common and Sun–Mercury oppositions are impossible.
Written and reviewed by the Zodiux editorial team · Last reviewed · Editorial standards and corrections · Astrology is for reflection and entertainment, not advice.
See which conjunctions are actually in your chart
The chart computes every pair in your browser, draws the aspects on the wheel and prints them by orb, so you can read the tight ones and ignore the tail. Birth details are never sent anywhere.
Is a conjunction good or bad?
Neither, and the conjunction is the aspect where that answer is most literally true. The other four angles carry a traditional character regardless of the bodies involved; 0° carries none, because the two bodies merge rather than relate. Venus conjunct Jupiter and Mars conjunct Saturn are the same angle and read in opposite directions. The only generic thing a conjunction tells you is that whatever those two bodies do, they do it together and loudly.
How close do two planets have to be to count as conjunct?
There is no universal answer, only a stated one. Zodiux counts a conjunction while the gap is 7° or less, in the natal chart and in the synastry engine alike, applied identically to every pair. Textbooks commonly allow 8° to 10°, and some widen it further for the Sun and Moon. Because the exact angle is zero, the gap is the orb: a pair 2° apart is a 2° conjunction. Tighter is stronger is the one rule everybody agrees on, so read the orb before you read the interpretation.
What do combust and cazimi mean?
They are traditional judgements about a planet's closeness to the Sun, based on whether it can still be seen. A planet within about 15° of the Sun is under the beams and read as dimmed; within about 8°30' it is combust, the weakest condition in the scheme; but within about 17 arcminutes it is cazimi, in the heart of the Sun, and read as the strongest. Cazimi is brief rather than rare — every Sun–Mercury conjunction passes through it, spending between 6 and 21 hours inside the band in 2026. Zodiux computes neither condition; it reports the conjunction and its orb.
Does the Zodiux chart show my conjunctions?
Yes. The free chart computes all 45 pairs among the ten bodies in your browser, draws each aspect on the wheel and lists the tightest by orb, with conjunctions appearing at 0°. It does not draw house cusps, does not aspect the Ascendant or Midheaven, and takes no view on combustion. The compatibility tool uses the same 7° orb across seven bodies but scores every conjunction as harmonious, which is a simplification worth correcting by hand when the pair is a difficult one.
How common is a conjunction in a birth chart?
Common, but not automatic. Sweeping the ten bodies weekly from 1980 to 2029 at a flat 7° orb gives an average of 2.28 conjunctions per chart, and 7.8% of charts have none at all. The distribution is lopsided, though: Mercury sits within 7° of the Sun on 20.5% of days and Venus on 10.7%, so a large share of all conjunctions are Sun–Mercury or Sun–Venus pairings that most charts in the room also have.