What Is A Supermoon And What Causes This Phenomenon?
The moon does not have a perfectly circular orbit but its orbit around the earth is elliptical in nature. The orbit is thus longer than it is wide. What does this implicate?
The elliptical or saucer-shaped orbit of the moon means that as the moon follows this orbit, it is at times closer to the Earth and at other times further away from our planet. Thus, the moon’s distance from our planet varies as the former revolves around the Earth in its orbit. Astronomers use the term perigee to indicate the position of the moon when it is closest to the Earth, and apogee is the term used to describe the position when the moon is furthest from the Earth. The difference between these two positions is about 31,068 miles.
The moon also appears in various phases as it revolves around the Earth depending on the extent to which the sun facing side of the moon is facing our planet. Thus, we can see 8 phases of the moon in one lunar cycle. These include the new, waxing crescent, first quarter, waxing gibbous, full, waning gibbous, last quarter, and waning crescent moons.
So, when we have a situation where we have the two phenomena of a perigee and a full moon (or new moon) overlapping, it results in a perigee moon or a SUPERMOON. The phenomenon occurs once in every 14 full moons. Occasionally, a supermoon phenomena might coincide with a total lunar eclipse.
Why Is The Supermoon So Special?
When the supermoon represents a full moon at perigee, the moon appears bigger and brighter from the Earth than the moon at other positions in its orbit. The perigee full moon appears as 14% bigger and 30% brighter than the apogee full moon.
How Did The Supermoon Get Its Name?
Astronomers originally referred to the phenomenon as the perigee full moon. However, the term supermoon found wider acceptance in common culture. Astrologer Richard Noelle claims to have coined the term “supermoon” in a 1979 article written by him for the Horoscope magazine.
Does The Supermoon Have Adverse Effects On Life On Earth?
For years, there have been speculations on whether supermoons could spell disasters on Earth. This thought is based on the fact that the gravitational pull of the new moon and the full moon are strongest and affects oceanic and crustal tides on Earth. Since during the perigee, the moon is closest to the Earth, the influence of the moon’s gravitational pull on objects in our planet is expected to increase. However, the calculations by scientists prove that this might not be the case as the change in the gravitational pull of the moon is not large enough to result in significant differences in tidal water levels.
Media have, however, several times in the past, portrayed that the supermoon is the harbinger of danger. The supermoon has been held responsible for the 2011 earthquake and tsunami in Tōhoku as well as the 2004 earthquake and tsunami in the Indian Ocean. As recently as November 2016, posts have been circulating in the social media that the New Zealand earthquake has been a result of a supermoon. However, scientists have denied any relation of the supermoon with the New Zealand earthquake or any other earthquakes and tsunamis.
Supermoons In The Past And Present
Supermoon prediction has always sent waves of excitement among the public at large across the world. Watching the supermoon shining brightly in the sky is an event celebrated by many. Supermoons coinciding with a total lunar eclipse is rare and once such event occurred on September 27–28, 2015 and the next will be in 2033.
The biggest supermoon of the 21st century can be seen in the sky on the night of 13th and 14th November 2016. The supermoon will be 14% larger and 30% brighter than the smallest full moons.