The Aspects between Planets
‘Aspects’ refer to the arc of separation or angular distance between the planets. They describe the ways in which planets can influence one another and modify each other’s expression. When planets are located at a certain distance from one another, they are connected in some intrinsic manner that is either harmonious or challenging.
Ptolemaic Aspects are the traditional major aspects used by Ptolemy in the 1st Century A.D. :The Conjunction (0°), the Sextile (60°), the Square (90°), the Trine (120°) and the Opposition (180°).
The book Johannes Kepler wrote in 1619 (Harmonices Mundi) describes thirteen aspects. All aspects are a division of a circle by different proportions or fractions also known as small whole number harmonics.
The main astrological aspects used by most western astrologers today are the Ptolemaic aspects (The Conjunction (0°), the Sextile (60°), the Square (90°), the Trine (120°) and the Opposition (180°) ) as well as the Quincunx (150°).