The Angles Between Planets

Aspects are the angular relationships between planets in a chart, measured in degrees around the circle. The classical five, the Ptolemaic aspects, are the conjunction (0 degrees), sextile (60), square (90), trine (120) and opposition (180); later astrologers, notably Kepler, added minor aspects such as the quincunx and semisquare.

Each aspect is a division of the circle by a whole number (the opposition halves it, the trine divides it in three, the square in four), and carries a character: the trine and sextile are read as easy or harmonious, the square and opposition as tense or challenging, the conjunction as a blending whose tone depends on the planets.