Sixty degrees, five degrees of orb
A sextile is a sixth of the circle. The orb allowed is five degrees, tighter than any of the other major aspects, which is a deliberate choice rather than an accident of tradition. The aspect is considered weaker, so it is given less room to operate in, and a Moon and Venus fifty seven degrees apart counts while a pair sixty seven degrees apart does not.
Sextiles link signs of compatible elements, fire with air and earth with water. A Moon in Taurus sextiles a Venus in Cancer or Pisces. The two signs are not in the same family, as they are in a trine, but they are in families that the tradition treats as cooperative. That partial agreement is the reason the aspect is described as conditional.
The Moon makes four sextiles to Venus in a lunar cycle, two on each side, so this is a common configuration in the sky and a common one in charts.
Compatible without being identical
The Moon governs the automatic responses, the sense of what is familiar and what constitutes rest. Venus governs judgement about pleasure and worth: attraction, taste, generosity, the terms on which you get along with people. A sextile between them means the two are on good terms without being fused.
Because the elements are compatible rather than the same, the descriptions tend to be about capacity rather than character. Someone with the aspect can make themselves agreeable, can identify what would make a situation more comfortable, can turn a private preference into something shared. Whether they do it is left open, which is exactly the difference between this aspect and a trine.
Astrologers who divide aspects into hard and soft place the sextile firmly on the soft side, but the more careful ones treat it as a hinge. Nothing forces the connection into use, and nothing prevents it either.
Where sign and house move the reading
The element pairing sets the tone. Earth with water gives a practical, tactile version: comfort you can point at, taste expressed in things rather than words. Fire with air gives a version that operates socially and verbally, quick to warm a room and less interested in the furniture in it.
Houses decide the arena. A Moon in the fourth sextiling a Venus in the sixth reads as a domestic life and a working life that support each other. A Moon in the eleventh sextiling a Venus in the ninth reads as friendships built around shared interests rather than shared history. Because a sextile only spans two signs, the two houses are usually close together, which tends to keep the aspect's effects in one region of the chart rather than spreading them across it.
Orb, speed and using the check above
The five degree limit does most of the work here. A sextile at one degree is worth reading properly. At four and a half it is at the edge of what the convention allows, and many astrologers would drop it in favour of a stronger aspect elsewhere in the chart. There is no wide sextile worth writing a paragraph about.
The Moon's speed makes this sensitive to birth time. Thirteen degrees a day means about half a degree an hour, so a birth recorded to the nearest hour carries enough uncertainty to matter when the orb is this narrow. If your time is approximate, treat a sextile near the limit as unconfirmed rather than absent.
Venus retrograde is read as reviewing rather than applying, and a stationary Venus is given extra weight. The check above reports the separation to the degree along with both signs, both houses and the direction of travel, so you can see whether the aspect is inside the orb or just outside it.
Questions people ask about this
What does Moon sextile Venus mean?
It means the Moon and Venus were sixty degrees apart at birth, within five degrees of orb. The tradition reads it as an easy but optional link between what comforts you and what you find worth having.
Why is the orb only five degrees?
Sextiles are treated as weaker than trines, squares and oppositions, so convention gives them a narrower window. An aspect that is considered less forceful is not allowed to stretch as far from exactness.
How is a sextile different from a trine?
A trine joins signs of the same element and is read as operating by default. A sextile joins compatible but different elements and is read as available on request. The trine happens to you, the sextile waits.
Does a wide sextile still count?
Not really. Beyond about four degrees most astrologers stop reading it as a working aspect, and beyond five the convention excludes it entirely. There is no useful equivalent of a wide trine here.
Can this aspect occur more than once a month?
In the sky the Moon makes four sextiles to Venus in each cycle, two approaching the conjunction and two approaching the opposition. Only the one in place at birth appears in a natal chart.
Does an uncertain birth time affect it?
Yes, more than for slower pairs. The Moon shifts about half a degree an hour, so an hour of uncertainty is meaningful when the whole orb is five degrees wide.