During the last few days the news are talking about the “Supermoon” happening on Monday 14th November. The reports (some examples here, here and here) say that “it will be the brightest Full Moon in years“. Even we at the Australian Astronomical Observatory have been asked about this “very rare phenomenon“. But how much is true about all of this?
Let’s take a look. First of all we should have clear that the Moon, as any other small body moving around a larger body, has an elliptical orbit.
Diagram explaining the movement of the Moon around the Earth. Not in scale. Credit: Ángel R. López-Sánchez. Moon image: Paco Bellido.
Planets also move around the Sun following elliptical orbits, as it was discovered by the great astronomer (and the first real astrophysicist in History, although he also had to work as an astrologer to get a salary) Johannes Kepler at the beginning of the 17th century.
This means that sometimes the Moon is closer to the Earth and sometimes it is farther from the Earth, just depending on where is is located within its orbit. The point on the Moon’s orbit closest to Earth is called the perigee (at an average ...