A stressful aspect between two planets
Aspect angle: 90 degrees
Unfavorable. When two planets form a square, they create a hard right angle to each other, stressing one planet's energy against the other. There's tension between the two planets in square, creating an atmosphere of discomfort and anxiety.
Take Uranus and Pluto, for example: When the planet of revolution and the planet of death and regeneration create a square, the effect may be a need to sweep away all the old ways of doing things and completely revolutionize your life. Uranus square Pluto is a powerful Astrology aspect that creates drastic change, but also opens the opportunity to a new and better way.
Not all planetary squares are as drastic as Uranus square Pluto, but in general, squares can be quite frustrating in the moment. Just remember, they do also bring an incredible opportunity for growth.