The application and separation of the Planets and Points are one of the most basic tenants to understanding Astrology and how it works. There are a variety of different methods in which Planets may apply and separate; all of which will be described below. Each Planet moves through the Zodiack Signs and degrees under their own specific speed. There are three main motions of the Planets, the first being Direct, where a Planet moves forward in degrees; for example, Saturn in the 1° of Aries moves to the 2° of Aries and then to the 3° of Aries. The second motion, or anti-motion of the Planets is a stationary. This means that the Planet does not move from its specific degree. This can last up to 4 days in the case of Saturn and less in the faster moving Planets. The last motion of the Planets is that of Retrogradation, or the appearance that the Planet is moving backwards (because of the movement of the earth). The Planet will make its path back through the degrees and Signs of the Zodiack. For example, Saturn in the 1° Aries goes retrograde and moves into the 29° of Pisces, then the 28° of Pisces and furthermore until he goes Direct again. The aforementioned anti-motion of Stationary happens just before a Planet is about to go into Retrograde or just before a Planet is about to go direct.
Each of the Planets is designated a speed. The Planets all move in progression of speed following the Traditional Cosmology chart. Because each Planet has a separate speed, it is inevitable that during specific times each Planet will meet another in one part of the Zodiack where it has conjunction or aspect unto the other Planet since the Planets do not all move at the same rate. The initiation into this conjunction or aspect is called application. Application happens until the Planet has become exactly joined to the Planet (or Point). Application can happen one of three ways.
The first method of Application is when two Direct Planets meet with each other in conjunction or Aspect. It should first be noted that it is impossible for a heavier Planet to apply unto a lighter one. By following the aforementioned chart of Traditional Cosmology, it can determined that Saturn cannot apply to Jupiter because it moves slower than Jupiter and therefore it is Jupiter that applies unto Saturn. Luna always applies to every Planet. This rule can be broken however with regards to Retrograde Planets. For a Planet moving Direct into an Application, then leaving in a separation, and turning Retrograde will make that Planet then re-apply to the Direct Planet. The first type of Application is called a Direct Application.
The second method of Application is when one Planet is Direct and the other is Retrograde. This means that a Retrograde Planet may conjunct or aspect another Planet up to three times, where as two Direct Planets would only aspect once. For example, Jupiter Direct and applying to Saturn Direct may after passing Saturn and separating from him, turn Retrograde and re-apply to Saturn a second time, and passing him again, and re-separating, Jupiter finds himself Direct again and for a third time passes over the conjunction or aspect with Saturn. The phrase bad things happen in three's is most likely a result of this occurrence happening.
The third method of Application is when both Planets are Retrograde and the quicker or lighter one Retrogrades into the orb of the slower or heavier one. This is the same scenario as the first Direct Application and thus is called Retrograde Application. Now it is appropriate to move onto Separation.
Separation is nothing more then when two Planets leave the perfect or Partile Conjunction or Aspect of the Planet they are joined with. For example, Jupiter in 1°00' Aries in Partile Conjunction with Saturn at 1°00' starts to separate from Saturn when Jupiter passes 1°17' of its Conjunction with Saturn who is still placed at 1°00'. The further the Planet moves from the perfect or Partile aspect, the weaker its influence becomes. Jupiter will not be fully separated from this Application until he hits his moeity or half point orb. In this example the moeity or half point orb of Saturn and Jupiter is 14°, therefore when Jupiter is 14° from Saturn, he has fully left Saturns influence. The rest of the orbs can be found on the Treatise regarding States of Sol. To conclude an important rule that should also be remembered is that a Planet applying is always stronger then a Planet who is separating.