👉 A quadrennium is a period of time in the life cycle of a celestial body, which can vary from 5 to 14 years. These periods are typically associated with major events such as the passage of a planet through its orbit or the appearance of a new planet. The term "quadrennium" is often used to refer to this period when a planet is in its closest approach to Earth, which can be observed from space. For example, during a quadrenn
