When you think of orbs and astrology, most often your mind will go to crystal balls and how they are used in divination. There is, however, another kind of astrological orb that you may know far less about and yet, in terms of astrology as opposed to divination, is far more important. Orbs in astrology are directly connected with the aspects. The ‘orb’ is the margin of influence that an aspect has to still be an influence over a sign. The orb is important for each of the aspects: conjunction, sextile, square, trine, and opposition, as well as the minor aspects of semi-sextile, semi-square, sesqui-quadrate, quincunx, and quintile. Historically, the orb and aspects would have been measured using a cosmo or astrolabe. Many astrologers limit the orb that an aspect can have. The smaller the orb, the greater and more significant the influence of the aspect is. Read more about natal charts and navigation here.
Astrology Orb and Aspect Calculation
So, the greatest influence an aspect will have is if its orb is at a single degree:
- If you are looking for Conjunction, then the orb should be 10.8 degrees or less.
- If you are looking at Opposition the orb should be 10 degrees or less.
- If you are looking at the Trine then the orb should be 8.3 degrees or less.
- When looking at the Square, you are looking for an orb of 7.5 degrees or less.
- The Sextile should have an orb of 5.7 degrees or less.
Minor Astrological Aspects
Among the minor aspects:
- The semi-square and sesqui-square should have equal orbs of 2.5 or less.
- The Quincunx should have an orb of 2.2 degrees or less.
- The Semi-sextile should have an orb of 1.5 degrees or less.
- Both the Quintile and Bi-quintile should have an orb of one degree or less.
How the orb is applied to the aspects depends on what sort of astrological reading you are looking for. For example, if you are looking for a compatibility reading, the nuances and inflections of your chart will be different because your chart is being compared to the chart of someone else to see how the different aspects and their orbs affect your interactions with another person. If you were just having a reading done to see if you should look at changing your job, or what may be coming up in your future then the astrologer doing your reading is only having to look at your information, not yours as well as the information of someone else. With a compatibility reading, not only do they have to analyze both of your charts, but then they have to figure out how each piece of both natal charts may react with one another.
In almost all cases, the planets will be within an orb of influence for an aspect, however, occasionally a planet is not an aspect to any other influence and is referred to as unaspected. These unaspected planets are considered loose cannons with energy that is either positive or negative: Mars, Saturn and Pluto unaspected are generally considered dangerous while Jupiter and Venus are frequently assets to a chart.