In a birth chart
Look for a skill assembled from two unlike parts. Mars in Virgo semisextile Mercury in Libra might describe someone who works precisely and must learn to present that work diplomatically.
Adjacent, minor aspect
Semi-Sextile
30°, 1/12
The semisextile is a 30° aspect, usually between planets in neighbouring signs that share neither element nor mode. It describes two parts of you that sit side by side but work in different ways, and it shows up as small, repeated adjustments you can learn to spot and use.
The essential reading
The semi-sextile connects planets one sign apart — signs which are always adjacent but fundamentally different in element and quality. This creates a relationship that is close yet incongruous: the two energies are aware of each other but do not naturally communicate well. It is a minor, subtle aspect that can feel like a background hum of mild discomfort or adjustment.
- Angle
- 30°1/12 of the circle
- Nature
- NeutralMinor aspect
- Harmonic
- 12thwith the Quincunx
- Tradition
- HarmonicOrb 2° standard
- Sign relationship
- Neighbouring signs: no shared element or modality (in aversion, traditionally)
Developmental arc
Adjustment
Managing the discomfort of two adjacent but incompatible energies. Because neighbouring signs are always in different elements and modalities, the semi-sextile rarely resolves into genuine harmony. The growth it offers is the capacity to tolerate ambiguity and make continual small adjustments.
Well integrated
Mild supplementary talent or an ability to bridge two otherwise unrelated areas of life. Can function as a low-level facilitator when part of a larger configuration.
Unresolved
A persistent low-grade friction or unease between two areas of life that refuse to fully integrate. The native may feel a vague sense of incompatibility between the planetary principles involved.
Interpretive contexts
A lasting pattern in one person
Natal chart
A subtle background tension or mild awkwardness between the two planets. Rarely a defining feature of the chart but can add nuance when the planets are otherwise strongly placed.
A moving planet meets a natal one
Transit
Barely perceptible. Generally only considered when reinforced by simultaneous stronger transits involving the same planets.
One person’s planet meets another’s
Synastry
Very minor influence. May add a subtle note of dissonance or mild cross-stimulation in the areas governed by the planets.
Technical data
25°exact 30°35°
- Standard orb
- 2°
- Tight orb
- 0.5°
- Signs apart
- 1
- Compatible elements
- No
- Shared modality
- No
- Harmonic
- 12th
Tradition
Medieval / Ptolemaic-era extension
Also known as
- SSxt
- Duodecile
- Adjustment
- Awkward
- Latent
- Subtle
- Adjacent
In the sky now
Live semi-sextiles
Pairs among the Sun, Moon and planets within 3° of an exact semi-sextile, measured from Earth right now.
What the semisextile means
A semisextile joins two planets about 30° apart, one twelfth of the zodiac, which usually puts them in neighbouring signs. Neighbours are built differently: Aries is Fire, cardinal and yang, while Taurus next door is Earth, fixed and yin. The two planets have no shared style to fall back on.
Modern astrologers read it as a working relationship that needs practice. Picture Venus in Leo semisextile Saturn in Virgo: affection wants to be shown warmly, while Saturn wants it to be useful and earned. The person may show love by quietly fixing things for a partner, then feel hurt that nobody noticed. Neither planet is wrong; they have to agree on a shared method.
- Keywords
- Adjacency, adjustment, practice, borrowing skills, step-by-step growth
- Nature
- Neutral in this catalog; some modern authors call it mildly helpful, others mildly awkward
- Asks
- What does each planet need to borrow from the other?
- Typical feel
- Sharing a desk with a colleague from another department: different priorities, some awkwardness, real usefulness once you learn their language
- Complementary skills. Mercury in Gemini semisextile Mars in Cancer: quick ideas backed by protective loyalty, so the person argues best for people they care about.
- A bridge between houses. Planets in the 10th and 11th linked this way can turn professional standing into a useful network, if the introductions are made deliberately.
The geometry of the semisextile
- 1
Convert to longitude
Sun at 28° Leo: the sign starts at 120°, so add 28°.
148°
- 2
Convert to longitude
Jupiter at 29° Virgo: the sign starts at 150°, so add 29°.
179°
- 3
Measure the gap
179° − 148° = 31°, already the shorter way round.
31°
- 4
Compare with exact
The exact semi-sextile is 30°; the gap is 1° away from it.
orb 1°
- 5
Check the allowance
With the Sun or Moon involved, this site allows 3°.
It counts
25°exact 30°35°
The semisextile measures 30°, one twelfth of the circle, so it belongs to the 12th harmonic, the family of angles made by dividing the zodiac into twelve. That family also contains the sextile, square, trine, quincunx and opposition. Only the semisextile (1/12) and quincunx (5/12) do not reduce to a simpler fraction, which is why they are read as a pair.
Sign relationship. By whole sign it links signs one apart, which never share an element or modality and always differ in polarity: Leo is Fire, fixed and yang; Virgo is Earth, mutable and yin. Hellenistic astrologers called such signs in aversion: they cannot see each other.
Out-of-sign exceptions. Mercury at 1° Libra and Venus at 29° Libra are 28° apart: a semisextile within a 2° orb, yet in one sign, a conjunction by whole sign. Mars at 29° Taurus and Venus at 0° Cancer are 31° apart, a sextile by sign. Read such contacts with both relationships in mind.
Applying or separating? The Sun moves about 1° a day, Jupiter about a twelfth of that. The Sun sits 31° behind and is closing, so the gap shrinks toward 30°: the aspect is applying, exact in a little over a day. After that the Sun keeps gaining, the aspect separates, and the pair heads toward a conjunction. A retrograde Jupiter would close the gap faster.
Inner-planet limits. Mercury never strays more than about 28° from the Sun, so a Sun–Mercury semisextile is possible only at the edge of orb. Venus reaches about 47° from the Sun, so Sun–Venus and Mercury–Venus semisextiles are common.
Orbs and how schools differ
- Tradition
- Medieval / Ptolemaic-era extension
- What that means
- Not one of Ptolemy’s four aspects: a later addition that entered common use in the early modern period with the semisquare and quincunx.
Hellenistic astrologers, working by whole sign, saw no aspect here at all, because adjacent signs are in aversion; they looked for rulership links instead. William Lilly gave each planet its own orb but applied them to the Ptolemaic aspects. Modern astrologers usually allow 1° to 3°, while harmonic astrologers following John Addey read the semisextile through the 12th-harmonic chart with narrow orbs.
Natal, transit and synastry at a glance
As a transit
Usually a small, practical adjustment: a new tool, an extra duty. Transiting Saturn semisextile natal Sun might bring one more responsibility at work. Handle it early and watch whether it grows under later transits.
Between two charts
Different ways of doing the same thing. Her Moon in Aries semisextile his Moon in Pisces: she wants to talk now, he needs a day first. A simple agreed routine removes most of the friction.
Common questions about the semisextile
Neither. It links signs with no element or modality in common, so the planets need practice to cooperate. The result can be a combined skill or a recurring small mismatch.
They read aspects by whole sign, and adjacent signs were in aversion, unable to see each other, so there was no aspect to interpret.
Orbit
Reading a semisextile step by step
A seven-step method for reading any semisextile, with a fully worked example.
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Orbit
The semisextile in relationships, work and inner life
Concrete scenes, one action and one pitfall for the semisextile in daily life.
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Orbit
Timing semisextile transits
How long semisextile transits last and how to use their short windows well.
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Astral
Advanced methods
Aversion, reception, declination, the 12th-harmonic chart and directions for the semisextile.
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Astral
Case studies
Three fictional charts showing how semisextiles play out and where readings compete.
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Astral
History, debates and sources
Where the semisextile came from, how schools read it and what evidence exists.
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