“What is a cusp? Why does my star mate chart mention cusps?”. This is a question that comes up quite a lot. Another one, which also comes up quite often, especially with the Moon, is “One of my planets is one sign off. Why is that?”
To answer the second question, we need to answer the first. From an astrological point of view, each of the planets move through each of the twelve zodiac signs in a continuous cycle. With the exception of the Sun itself and the Moon, the farther out the planets are from the Sun, the longer they take to complete a cycle. For the purposes of Astrology, the Sun and Moon are considered planets, however they are planets in an Earth-centric Universe. The Sun goes through approximately one sign every 30 days, and the Moon every 2-3 days.
The day of the change is considered the cusp. Sometimes the cusp is longer than a day, depending on how far the planets are out. For our purposes here at Star Mate, we use 1 degree within range of the next or previous planet to be considered “on the cusp”.
Now, if we used Time of birth in our calculations, that would tell us exactly which sign a cusp planet inhabits, and if we were trying to do a Natal Horoscope, we would indeed use that. However Star Mate is about the energies that are expressed, and a waxing or waning cusp sign can often have more power over a person’s emotions and thought processes than the low energy sign that it may have just entered. As a planet moves through a sign, it picks up more of that sign’s energy, before stepping off into the next sign and starting again.
Star Mate does a series of calculations to determine which sign it will display, but to let you know, it also adds a little message about the cusps – hence this article!