What Is the Interplanetary Phase?

When planets, the four major angles (such as the Ascendant (ASC), Midheaven (MC), etc.), Arabic Parts (such as the Part of Fortune, etc.), and other sensitive points in a natal chart form specific angular relationships, this is called an aspect in astrology. Astrologers define an allowable range (an orb) based on the strength of the planet’s influence or the aspect itself, and any angle that falls within this range is considered an aspect.

Aspects amplify the influence of the planets involved in a natal chart and carry distinct interpretive meanings; they result from the interaction of two or more planetary energies.

Aspects are often classified as harmonious or challenging. Harmonious aspects foster ease and support, while challenging aspects can introduce flaws and obstacles.

Commonly used aspects include 0 degrees (conjunction), 60 degrees (sextile), 90 degrees (square), 120 degrees (trine), and 180 degrees (opposition). Among these, 60 degrees and 120 degrees are considered favorable, indicating strong resonance between the planets, though the resonance at 60 degrees is somewhat weaker. Individuals with many of these aspects in their natal chart tend to express the planets’ positive energies and qualities more naturally. Conversely, 90 degrees and 180 degrees are challenging aspects, indicating discord between the planets that can manifest as less constructive traits. In general, the negative effects of oppositions are considered stronger than those of squares.