August 11, 2022
Image credit: Image credit: AP Photo/Mark Baker
Tonight’s full Sturgeon Moon will be the last supermoon of the year!
The Sturgeon Moon rounds out this year’s parade of four supermoons, which started in May. It will be visible from Thursday evening and at its peak on Friday, August 12, at 11:35am AEST: don’t be put off by its mid-morning debut – the supermoon will still be shining as the sun sets on Australia.
What is a Supermoon?
A supermoon occurs when a full Moon coincides with its closest approach to Earth – its perigee.
Australian Astronomical Observatory astronomer Fred Watson says a supermoon is defined by a full moon occurring at the nearest point to the Earth on the moon’s orbit.
Due to this proximity, supermoons appear seven per cent larger and 16 per cent brighter than the average full moon.
There can be three or four supermoons each year.
The ‘Moon illusion’
The increased size and brightness of supermoons generally go unnoticed and are often overshadowed by what’s known as the ‘Moon illusion’ – an optical illusion when full moons appear super large and bright when close to the horizon and surrounded by trees and buildings.
Why is it called the Sturgeon Moon?
According to the The Old Farmer’s Almanac, Full Moon names come from a number of places, including Native American, Colonial American and European sources.
August’s full Moon was traditionally called the Sturgeon Moon because the giant sturgeon of the Great Lakes and Lake Champlain in the USA were most readily caught during this part of summer.
What is a Sturgeon?
These prehistoric-looking fish have been traced back to around 136 million years ago and many people call them “living fossils”.
- Females require around 20 years to start reproducing, and they can only reproduce every 4 years. However, they can live up to 150 years.
- Today, there are about 29 species worldwide, including the lake sturgeon found in the Great Lakes. They have evolved in size from the size of a bass to monster sturgeon as big as a Volkswagen.
- The lake sturgeon is quite rare today, due to intense overfishing in the 19th century, pollution and damage to their habitat.
And don’t miss the Perseid Meteor shower tomorrow night
One of the best-known meteor showers, Perseid, puts on a good show every year, raining down shooting stars.
Visible from 17 July to 24 August, it peaks on the evening of 12 August, and into the following morning.
At this peak it produces up to 60 meteors per hour.
“The meteors are tiny fragments, mostly smaller than a grain of rice, that burn up in the atmosphere of Earth,” explains Macquarie University astronomer Professor Orsola De Marco.
“The Perseid meteor shower happens each August as Earth passes through the trail of debris shed by the Swift-Tuttle comet, an icy ball of rocks and gas 26km wide made up of remnants of the formation of our solar system, which last crossed Earth’s orbit in 1992, and returns every 133 years.”
Unfortunately, Perseid coincides with a full moon in 2022, making it less visible from Australia this year.
Nevertheless, look up 3am (AEST) on 13 August for the best chance to see it.