iVillage

This diagram shows how the Earth in its yearly orbit, cycle or circle actually is always moving forward (we mentioned the speed!), so it really makes more of a spiral than a simple circle. These circles spiral.

Summary: All circles—and in fact everything that repeats or returns on itself again and again—cycle, and these cycles are spirals. Examples of common cycles are the cycle of the Earth around the Sun in a year, the cycle of the Moon around Earth in a month, the cycle of the revolution of the Earth in a day, the cycle of our breath breathing, the cycle of our heart beating, and so on, downward to cycles so small that they are invisible to us, like the cycle of electrons orbiting an atom.

On the other hand, cycles beyond our imagination on the longer side include the cycle of our Sun orbiting the center of the galaxy (in some 230 million years) and so on. In other words, we are bound on the one hand by endless cycles too small for us to measure and on the other by cycles too vast for us to grasp. We study the cycles that fall within our life’s awareness and our ability to measure and understand. In many ways, astrology is the study of these cycles.