Mercury Square Venus

The arithmetic settles it. Mercury's greatest elongation from the Sun is about twenty eight degrees, Venus's about forty eight, and when the two sit on opposite sides of the Sun at their extremes the separation reaches roughly seventy six degrees. That is the widest the pair can be. A square requires ninety, and ninety is fourteen degrees beyond the physical limit. This is not a rare configuration or a debated one. It does not occur, has never occurred, and will not occur while the planets keep their present orbits.

Why it appears in books and printouts anyway has three ordinary explanations. Software that generates every pair against every aspect will emit the impossible ones unless someone has thought to forbid them. Sign based reading produces a convincing illusion: Mercury at twenty degrees of Aries and Venus at six degrees of Cancer are in square signs while being seventy six degrees apart, which is a wide sextile and behaves like one. And in synastry the square is entirely real, since one person's Mercury may sit ninety degrees from another person's Venus without difficulty.

A reader who arrived here almost certainly has one of three things. A Mercury Venus conjunction, which is common and worth reading properly. A genuine sextile, which is the widest real contact and the most useful. Or a square by sign only, in which case the sign natures are worth weighing but the aspect is not. It is worth noting that a trine or opposition cannot even be faked by sign, since those require at least ninety and a hundred and fifty degrees respectively. Only the square produces the illusion.