It might sound like the start of a joke, but there is indeed a common denominator.
So just what do werewolves and king tides have in common?
The Moon, and its size in our sky. As many people throughout history have noted, the Moon can appear at different sizes during the year. When it is especially big and bright, we tend to notice our closest celestial neighbour most.
What are supermoons?
So why does the Moon appear bigger on some nights of the year?
The Moon has a 28-day orbit, where at some points it is closer to earth (the closest point called perigee), and some points it is further away (apogee). This is because the Moon has an elliptical orbit.
When the Moon is at its closest point (its perigee), that is when it appears largest in the sky, what we refer to as a supermoon.
So, why are supermoons important?
Sure, they're cool to look at but supermoons can also have noticeable effects on life on earth. They have effects on organisms, light, and tides. Many people know about circadian rhythms that affect our sleep patterns. But not many people know that there is such a thing as circalunar rhythms. There are many examples of circalunar rhythms affecting animals' reproduction and nocturnal behaviours. Circalunar rhythms are related to light levels, as light pollution increases when there is a bigger/ brighter Moon.
The Moon's gravity influences tides on earth. When the Moon is closer to its perigee, then oceans are at a higher tide, often at maximum heights called king tides. It is important to know when these king tides will occur for many reasons including safety and observing rising sea level impacts.
When and where can you see them?
The biggest supermoon this year occurred on June 14. This supermoon was referred to as a strawberry supermoon.
Its name is not to do with its colour, but because the fruit is in season in the summer (in the Northern Hemisphere). It can also be called the hot moon, rose moon or mead moon.
The June 14 supermoon may have been the biggest so far this calendar year, but is by no means the biggest in recent history, which was the supermoon on November 14, 2016.
The next supermoon will take place on Thursday. The July 14 supermoon is referred to as the Buck moon, which is important for North America as it signals the season where male deer antlers grow the fastest.
Supermoons are a great event to see as they are visible all around the world. So, just like the June 14 supermoon, the July 14 supermoon will be visible all over the country.
The best time to see the full Moon is around moonrise on July 14. This is also the same time as sunset - when the sun sets in the west, the Moon is rising in the east.
If you want a great view of the next supermoon, try to go up a mountain, and get a nice view to the eastern horizon.
- Amy Briggs is undergraduate student at ANU studying science communication, with special interest in astronomy and astrophysics.
