Sixty degrees and the tightest orb
A sextile is a sixth of the circle. The orb allowed is five degrees, noticeably tighter than the seven given to a trine or the eight given to a conjunction, and that tightness is the point rather than an accident of convention.
The Moon makes two sextiles to Jupiter per circuit, so about twice a month. Moving thirteen degrees a day it crosses the ten degree band in under a day, and holds inside a single degree for roughly ninety minutes. This is a birth time aspect in the strictest sense.
The two bodies land two signs apart, which pairs fire with air or earth with water. Those combinations are read as compatible without being identical, and that is the usual explanation for why a sextile assists rather than merges.
An offer, not a given
The standard distinction is that a trine gives and a sextile offers. The resource is present but it has to be picked up, and if it is not, the chart reads as though the aspect were absent.
Here the offer is a workable relationship between instinct and expansion. Jupiter widens what the Moon reaches for, but at sixty degrees rather than joined, so there is a small gap where judgement can operate. In practice it tends to show as people who are good company, recover from setbacks reasonably quickly, and are willing to try something without needing certainty first.
It is a modest aspect. Nobody's chart is defined by a sextile, and a page that told you otherwise would be selling something.
The other reason to keep expectations low is statistical. A sextile between these two turns up in a great many charts, and the description attached to it is agreeable enough that almost anyone would accept it. That is a reason to weigh it lightly rather than to dismiss it.
Sign, house and what actually shifts it
Because the orb is narrow, the first question is always whether the aspect is really there. A four degree lunar sextile is at the edge of what most practitioners will read, and a rounded birth time can easily account for that much.
Where it is tight, the house pair sets the subject. A sextile from the third to the fifth house behaves nothing like one from the sixth to the eighth, though the angle is the same. Element pairing sets the manner: fire and air is quick and social, earth and water is slower and more practical.
Other aspects to the same degrees outweigh it easily. A tight square from Saturn to that Moon will be doing far more in the chart than the sextile will.
It is also worth asking which sextile you have. The one formed before the monthly conjunction and the one formed after are geometrically distinct, and some practitioners read the applying version as the more active of the two.
Jupiter's pace and what is shared
Jupiter needs about twelve years for a full circuit and spends roughly a third of each year retrograde, so a natal retrograde Jupiter is the common case and carries no special weight here.
Everyone born in the same few weeks shares Jupiter's position closely. What separates one chart from another is the Moon, and with it the orb and the houses, both of which need a birth time to be worth anything.
The check above reports the exact separation in degrees and minutes. With a sextile that number matters more than usual, because five degrees is the whole allowance and the difference between a real aspect and a coincidence of the chart wheel.
Questions people ask about this
Why is the sextile orb only five degrees?
Sextiles are treated as the weakest of the five major aspects, so the tradition allows them less room. Beyond about five degrees the two bodies are generally read as unconnected.
What does Moon sextile Jupiter mean?
It means the Moon sits sixty degrees from Jupiter at birth. The reading is a helpful relationship between instinct and expansion that has to be taken up deliberately rather than one that operates by itself.
How often does the aspect form?
Twice in each lunar circuit, so roughly twice a month, each pass staying inside the five degree orb for less than a day. It is common in the population but rarely tight.
Is a sextile weaker than a trine?
Generally yes. Both are read as supportive, but a trine is described as automatic while a sextile requires effort, and the narrower orb reflects that lower weight.
Does a rounded birth time matter?
It matters a great deal with a five degree orb. The Moon moves about half a degree an hour, so a time rounded to the nearest hour already carries meaningful uncertainty in the result.
What are the sign pairings?
Sixty degrees is two signs, so a sextile pairs fire with air or earth with water. Those are the combinations the tradition reads as cooperative without being interchangeable.