Sixty degrees and five degrees of allowance
A sextile is a separation of 60 degrees, and the orb used here is five, tighter than the seven allowed to squares and trines. That narrower allowance reflects the traditional view that a sextile is a weaker contact, so a wide one is not really a contact at all.
Mars and the Sun form two sextiles in each of their cycles of about twenty six months. Around a sixty degree elongation Mars is well clear of its retrograde station, so it is moving direct and reasonably briskly, and the aspect passes fairly quickly.
In the sky, Mars at this elongation is visible either low in the west after sunset or low in the east before dawn, depending on which side of the Sun it sits. It is neither hidden in the glare, as at conjunction, nor dominating the night, as at opposition.
Available rather than automatic
Signs sixty degrees apart pair earth with water or fire with air. They are compatible without being identical, which is the structural basis for how the aspect is read: the two bodies can cooperate but have to make an effort to understand each other, and that effort is small.
The Sun is conscious purpose. Mars is the drive to act on it. At sixty degrees the tradition reads someone who can find the energy for something when they decide to, without either the fusion of a conjunction or the running argument of a square. Descriptions tend towards competence, a workmanlike approach to effort, and a reasonable tolerance for competition without much appetite for picking fights.
The conventional qualification is that a sextile does nothing on its own. It is described as an offer standing open. Whether it is taken up is not something the chart claims to know, and this site is not going to claim it either.
Elements, houses and how tight the orb is
Which pair of elements you have changes the reading substantially. Sun in Taurus sextile Mars in Cancer is earth and water, read as patient and protective effort. Sun in Aquarius sextile Mars in Aries is air and fire, read as quick and argumentative. Applying one description to both would be sloppy.
Houses supply the subject. The same sextile between the tenth and twelfth houses and between the third and fifth describes entirely different areas of life. Because houses depend on birth time, a rounded or approximate time leaves that part of the reading uncertain even when the aspect itself is secure.
Orb is the strictest filter here. With only five degrees of allowance, a sextile at four degrees is close to the edge and worth very little. Inside one degree it is genuinely worth reading. There is not much middle ground.
What to take from the check
The honest position on this aspect is that it is a supporting detail in most charts rather than a headline. Any conjunction, square or opposition involving the Sun or Mars will speak louder, and a good reading says so instead of giving equal weight to everything it finds.
What the check above supplies is the part that is not negotiable: the exact separation, the two signs and their elements, the houses, and whether the aspect is applying or separating. If the separation comes back near five degrees, you can reasonably set this page aside.
If it comes back tight, read the element pairing first and the general description second. That order matters, because the elements carry more information about how the aspect behaves than the sixty degree angle does on its own.
Questions people ask about this
Why is the sextile orb only five degrees?
Because the tradition ranks the sextile as a minor harmonious contact rather than a major one. Squares and trines get seven degrees and conjunctions and oppositions get eight. Beyond five, a sextile is not treated as an aspect here.
Is Mars direct when sextile the Sun?
Yes. Mars stations retrograde at an elongation of about a hundred and thirty seven degrees, far beyond a sextile, so at sixty degrees it is always in direct motion and moving at a fair clip.
Which elements does a sextile join?
Earth with water, or fire with air. That compatibility without identity is the reason the aspect is described as cooperative but requiring a small deliberate step.
Is Sun sextile Mars worth much in a reading?
Only when tight. Inside a degree or two it is a real feature. Nearer the edge of the orb it will almost always be outweighed by stronger contacts, and a careful reading will rank it accordingly.
How often does the aspect form?
Twice in each Sun and Mars cycle of roughly twenty six months, once on each side. The five degree orb keeps each window short, so it is briefer than the equivalent trine.
Can a sextile be out of sign?
Yes, when the aspect is wide enough that one body sits in the last degrees of a sign and the other in the first degrees of a sign sixty degrees away, breaking the usual element pairing. Out of sign sextiles are read as weaker again.