← Encyclopedia of Astrology · lesson 110/235
Applying
An aspect is applying when the planets are moving toward the exact angle: the orb is shrinking. Usually the faster planet is behind and catching up with the slower one. In William Lilly's terms, the lighter (swifter) planet "applies" to the weightier (slower) one — the order of speed runs Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn, then the outer planets.
A worked example
Mars at 10° Aries and Saturn at 14° Aries are conjunct with an orb of 4°. Mars is moving about 0.7° a day and Saturn about 0.1°, so Mars gains roughly 0.6° a day: the conjunction is applying, and it will be exact in about a week. Once Mars overtakes Saturn and moves on, the same conjunction becomes separating.
Retrograde motion
Speed and direction both count, which is where retrograde planets complicate things. William Ramsey distinguished a "direct" application, both planets moving forward, from one where a retrograde planet moves back toward the other — two planets can close on each other from both sides. A planet that turns at a station can also change an aspect's state: a separating aspect can become applying again, which is how an outer planet comes to cross the same natal point three times. In the charts here applying and separating are worked out from each body's actual speed at that moment, so a retrograde planet is handled correctly. When neither body has a motion of its own — two angles, say — the question has no answer and none is shown.
How readings use it
An applying aspect is read as building: the matter it describes is gathering, becoming more noticeable, and still ahead. Many astrologers find applying aspects in a birth chart stronger or more developing than separating ones — something the person grows into. In transits, applying is the run-up to the peak, often when a theme first appears. In horary, an applying aspect between the significators is what promises a matter will come about, unless something intervenes — another planet reaching one of them first (prohibition), or one turning retrograde before the aspect completes (refranation).
Where the charts here show applying beside an aspect, it is shown next to its orb and strength, not folded into them: a tight separating aspect and a wide applying one both have something to say.