What an orb is, and why 8°

Orb · conjunction & opposition 8° · trine & square 7° · sextile 5° · minor aspects 2-3° · Sun/Moon get ×1.25

01An angle, and a tolerance around it

An aspect is a claim about the angular distance between two bodies on the chart wheel: a conjunction is a claim that they sit at the same degree, zero degrees apart; an opposition, that they sit exactly across the wheel from each other, 180 degrees apart; a trine, 120; a square, 90; a sextile, 60. In practice two bodies almost never land on those exact figures — real positions are continuous, and an exact 90.000 degrees between two planets is a coincidence, not the normal case. An orb is the tolerance around the exact angle that still counts as the aspect: if two bodies are 87 degrees apart and the square's orb is 7 degrees, the aspect is counted, because 87 sits within 7 degrees of 90.

Lizastro's default orb table gives the widest tolerance, 8 degrees, to the two aspects measured from the most fundamental angles in the system — the conjunction, at 0 degrees, and the opposition, at 180. A trine at 120 degrees and a square at 90 both get 7 degrees. A sextile, at 60, gets 5. The quincunx, at 150 degrees, gets 3, the widest of the minor aspects. The remaining three minor aspects — the semisextile at 30 degrees, the semisquare at 45, and the sesquiquadrate at 135 — each get 2, the narrowest tolerance in the table. Every one of these figures is a stated default, printed on the chart it was used for, and every one of them can be narrowed by a user who wants a stricter reading. None of them can be widened past the default, on purpose.

02Why the tolerance exists at all

The tolerance is not a hedge against imprecision in the calculation — the ephemeris behind a Lizastro chart resolves a planet's position to fractions of an arcminute, far tighter than any orb in the table. What the tolerance is standing in for is a genuine astrological claim: that an aspect's effect does not switch on and off at a single exact degree but fades in gradually as two bodies approach the angle and fades out gradually as they separate from it. An orb is the width of that fade, stated as a number rather than left to intuition.

That fading is not treated as all-or-nothing inside the orb either. Lizastro scores every aspect it finds on a scale from zero to one, built from two things multiplied together: how tight the orb actually is, on a straight line from the maximum tolerance down to an exact hit, and how significant the two bodies involved are generally taken to be. Every body carries a weight for this second part — the Sun and Moon sit at the top, weighted 1.0 each; Mercury, Venus and Mars sit at 0.8; Jupiter and Saturn at 0.7; Uranus, Neptune and Pluto, the slow outer planets, at 0.5; the lunar nodes and Lilith around 0.35 to 0.4; the smaller asteroids at 0.2. A contact's importance is the average of the two bodies' weights, and the final score multiplies that average by how close the orb sits to an exact hit.

Worked through with real numbers: a square between the Sun and Mars at an orb of half a degree, against the luminary-adjusted tolerance of 8.75 degrees, has a tightness of about 0.94 — one minus half a degree over 8.75 — multiplied by an importance of 0.9, the average of the Sun's 1.0 and Mars's 0.8, for a strength around 0.85, close to the top of the scale. A quincunx between Venus and Saturn sitting near the edge of its own 3-degree tolerance, at an orb of 2.6 degrees, has a tightness of only about 0.13, multiplied by an importance of 0.75, for a strength close to 0.1 — technically found, and technically real, but near the bottom of the scale and correspondingly minor in how the reading treats it. Both aspects were located by the same orb table. The strength score is what tells the interpretation layer which of them is actually worth writing a sentence about.

03One exception, stated as a rule: the luminaries

The Sun and Moon get a wider tolerance than the base table lists — every orb involving either one is multiplied by 1.25 before it is applied, a traditional allowance for the two bodies every older system singled out as the lights. In practice that means a Sun or Moon conjunction is measured against 10 degrees rather than 8, a Sun or Moon trine against 8.75 rather than 7, and so on down the table. The multiplier is not a special case invented for this product; it reflects a long-standing convention that the two luminaries carry a heavier presence in a chart than any other body and are given correspondingly more room to still count as connected.

04Narrower for a moving contact

A transit is measured against a tighter version of the same table — exactly half of the natal orbs, so a transiting conjunction needs to come within 4 degrees rather than 8 to count, a transiting square within 3.5 rather than 7, a transiting sextile within 2.5 rather than 5, and down the rest of the table in the same proportion. The reasoning is about what a transit actually is: a natal aspect is a permanent feature of the chart, so even a wide 8-degree orb still describes something the person carries for life, while a transit is a moving contact that has to be close enough to be felt on a specific day. An 8-degree orb applied to a transit would report a dozen contacts as active on any given date, which is functionally the same as reporting none — nothing would distinguish one day from the next, and a daily reading built on that would drift toward the same generic weather regardless of the actual sky. Halving the tolerance is what keeps a transiting reading meaning something, and keeping the halved table exactly proportional to the natal one means a reader who narrows their own natal orbs gets a transit table that narrows by the same relative amount, rather than two settings drifting out of step with each other.

Every aspect Lizastro reports, natal or transiting, also carries a direction: applying, meaning the two bodies are still closing toward the exact angle, or separating, meaning they have already passed it and are drawing apart. The distinction comes from comparing each body's own speed and position a small step forward in time — if the gap between them is shrinking toward the exact angle, the aspect is applying; if it is growing, it is separating. An applying aspect reads as something still building or still arriving; a separating one reads as something already established, already lived with. Two aspects can share an identical orb and an identical strength score and still describe a different moment in the same underlying contact, depending only on which side of exact they fall.

05What it is not

8 degrees is not a measured constant of nature, discovered rather than chosen, and stating it plainly avoids the more common and quieter mistake: presenting a school's convention as if it were a law the sky obeys. The default orb table is exactly that — a convention, the set of values common in modern Western practice, chosen because they are widely recognisable and stated as a starting point rather than a discovery. A different tradition, or a different practitioner, might reasonably use a narrower or wider table for reasons of their own, and neither table is more correct than the other in any sense a telescope could settle.

What the product will not do is widen the table to manufacture a reading. A tool that quietly loosens its orbs when a chart looks sparse is not being more thorough — it is inventing contacts that are not really there in order to have more to say, and every extra degree of tolerance added after the fact makes the aspect list less honest about what it actually found. Narrowing is always available to a reader who wants a stricter, sparser chart. Widening past the stated default is not offered, because a wider orb does not reveal a hidden connection — it fabricates one.

06Where you see it in your own chart

Every aspect on a Lizastro chart is shown with its own orb, in degrees and minutes, alongside whether it is applying — still closing toward the exact angle — or separating, already past it and drawing apart, and alongside the strength score built from both the orb and the two bodies involved. A tight orb, well under a degree, reads as close to constant in a life; a wide one, near the edge of its tolerance, reads as present but considerably less pronounced, and the strength number underneath both is what lets the two be compared directly rather than only described in words.

→ See the orbs on your own chart · Read the full methodology

07Related reading

House systems are the other place a single stated default shapes what a chart shows without changing where anything actually is — six ways of dividing a wheel, one printed choice among them. Lilith's mean and true variants are a different kind of tolerance question: not how wide a match can be, but how far two legitimate calculations of the same point can land from each other.

Updated 2026-08-05.