heyday is the masculine noun of the scope of astronomy which indicates the farthest point that a celestial body presents in relation to the Earth.
In figurative meaning, the word apogee means the peak, Hight point, acme or climax of something. Ex: The heyday of the Brazilian team happened in 1982, despite not having won the World Cup.
Originating from the Greek word apogees, it is formed by the joining of apo (which means far) and geo, which means "earth".
Apogee and perigee
Apogee and perigee are two concepts in astronomy, which indicate the greatest distance (apogee) and the shortest distance (perigee) of a celestial body in relation to planet Earth.
In the specific case of the Moon, when it is in its perigee, it can be approximately 50 thousand kilometers closer to the earth than when it is at its peak, which greatly modifies its appearance.
We know that the physical dimension of the Moon does not change over time, just as its volume remains the same. However, its appearance can change depending on its stage. When it is closer to Earth (perigee), the Moon appears to be much larger and brighter.