What is a Supermoon? All you need to know about the facts and myths of the astronomical event

The only supermoon of the year is slated to occur on 3 December, when the moon is expected to appear closer and brighter than usual. The term supermoon has reportedly been used for the past 40 years or so.

The recent hype surrounding the supermoon, especially given how 2017 has only one occurring, may lead some to assume that the astronomical event occurs rarely. In reality, supermoons occur fairly frequently. The closest supermoon recorded in nearly 70 years reportedly occurred in November 2016. The next closest supermoon, closer than the one that occurred last year, is expected to occur in the 2030s, Space.com reported.

What is a supermoon and how does it work?

A supermoon occurs when a full moon coincides with the moon's closest approach to the Earth in its orbit. Given the moon's elliptical orbit, it reaches a point where it is farthest from the Earth ( apogee - 405,500Kms) and a point where it is closest to our planet (perigee - 363,300Kms), according to Nasa.

"Full moons can occur at any point along the Moon's elliptical path, but when a full moon occurs at or near the perigee, it looks slightly larger and brighter than a typical full moon. That's what the term 'supermoon' refers to," Nasa JPL's educational technology specialist Lyle Tavernier recently wrote in a blog.

Here is a list of the most important facts and common myths about supermoon:-

Facts:

• The moon can appear brighter by as much as 30% and around 14% larger.
• Despite the increase in size and brightness, the difference may still not be clear to the naked human eye.
• The term supermoon was first coined by American astrologer Richard Nolle in an article in 1979.
• 2016 saw three consecutive supermoons occur in October, November and December.
• Three more supermoons are expected to occur in 2018 – two in January and one in February

Myths:

• Despite some non-scientific speculation, a Supermoon does not cause any natural disasters. Nasa's Tavernier said that "a supermoon will not cause extreme flooding, earthquakes, fires, volcanic eruptions, severe weather, nor tsunamis."
• The Moon does not appear larger during moonrise – this is an optical illusion called the Moon illusion. However, scientists are still unsure of what causes this illusion.