The word "supermoon" was coined by Richard Nolle, an astrologer, in 1979.
A supermoon occurs when the full moon coincides with the moon's perigee- the point of orbit when the moon is closest to earth.
On the night of December 3, the sky-watchers across the globe will witness the first and last observable supermoon of 2017. It has also been adopted by some with the term micro-moon or mini-moon when the full moon coincides with the apogee. The variations in apparent size and illumination amount to few percent but they can improve the already incredible sight of the full moon, making a supermoon worth looking up for. Syzygy means when the sun, moon and earth fine tune and come in a straight line.
December's full moon officially occurs at 10:47 a.m. Sunday.
In the perimeter the Moon will be 357,492 kilometers away from the Earth, while at the time of the full moon a little more (357,987 km).
As a result, the moon appears to be up to 14 percent larger and 30 percent brighter during a supermoon.
If you somehow manage to miss this supermoon or forget about it, don't worry: January has two supermoons! The moon should sit near the constellation Taurus, though it shouldn't be hard to spot.
The supermoon will be visible in night skies around the planet, but the best time to see it will be just after sunset. In this position, the moon looks larger and brighter than when it rises up in the sky, because when it is low, one can compare it with elements of the landscape (hills, buildings, etc.).
The moon will actually be closest to Earth at 4 a.m. on Monday.
Supermoons do not cause extreme flooding, earthquakes or other natural disasters, NASA says.