Planets are rarely separated by the exact number of degrees listed for the different aspects, so astrologers use an orb of influence.
If the orb is tight (close to being an exact aspect), the aspect is more powerful. If the planets are linked by a wide orb aspect, their influence is not as strong.
Astrologers vary in the number of degrees they use for these orbs. Some base the orb on the planet involved, others assign a different orb based on the aspect. But as a general rule, you can use
- 7 to 8 degrees of separation for the major aspects
- 1 to 3 degrees for minor aspects.
- The Sun and Moon are often given larger orbs, up to 10 degrees for the major aspects.
- Uranus, Neptune and Pluto are often given smaller orbs, up to 5 degrees, because they move very slowly.
- Points in the chart, such as the Ascendant, Midheaven, Part of Fortune, or the Moon's Nodes are often given tight orbs of only 2 degrees.
Orbs of only 1 degree are often used when looking at the movement of the chart over time, for example examining transits (the position of the planets on a particular day in relation to the natal chart) or progressions (where the movement of the planets over the course of one day is equivalent to one year of life).In these cases, there is also more emphasis placed on an approaching aspect (the aspect is becoming more exact) than on the separating aspect (an aspect where the planets are moving away from exact).