Because the Moon has no light of its own, it has to rely on the Sun to provide its familiar white glow at night.
As the Moon orbits the Earth throughout the month, different amounts of its planet-facing side are illuminated.
This results in four distinct lunar phases: the invisible New Moon, the First Quarter Moon, the brightly lit Full Moon and the Third Quarter Moon.
In between these four phases, you will notice the Moon takes on a crescent shape, particularly just before and after the New Moon.
Space agency NASA explained: “Moonlight is sunlight bouncing off the Moon’s surface.
“As the Moon orbits Earth, the Sun lights up whatever side of the Moon is facing it. To the Sun, it’s always a full Moon.”
When is the October Full Moon?
The Full Moon will fully light up next week in the afternoon hours of Wednesday, October 24.
NASA said the Moon will peak in brightness at 5.45pm UK time (4.45pm UTC or 12.45pm EDT).
But stargazers hoping to catch a glimpse of the Moon will have to keep in mind their exact location and adjust accordingly.
When viewed from London for instance, the Moon will not rise over the horizon until 6.16pm BST.
Further up north in Glasgow, Scotland, moonrise is expected to occur a whole ten minutes later.
Someone watching the Moon from Rome, Italy, will have to wait until 6.45pm local time and Moscow will not see the Full Moon until 7.45pm local time.
NASA said the Moon will appear full for about three days, meaning on the day before and after the Full Moon, you will be very hard pressed to see a difference in illumination.
The space agency said: “In lunisolar calendars the months change with the New Moon and Full Moons fall in the middle of the lunar month.
“This Full Moon falls near the middle of the ninth month in the Chinese calendar and Marcheshvan in the Hebrew calendar.
“In the Islamic calendar the months start with the first sighting of the waxing crescent Moon a few days after the New Moon.”
What is the meaning of the October Full Moon?
Keen astronomers might recognise the October Full Moon as the so-called Full Hunter’s Moon or just Hunter’s Moon.
The name derives from Native American Algonquin tribes who named the different phases of the Moon to keep track of time.
NASA said: “According to the Farmer’s Almanac, with the leaves falling and the deer fattened, it is time to hunt.
“Since the harvesters have reaped the fields, hunters can easily see the animals that have come out to glean.
“The earliest use of the term ‘Hunter’s Moon’ cited in the Oxford English Dictionary is from 1710.”