Once In A Blue Moon...
A Stunning Rare Blue Moon Will Be
Visible Over Sydney This Week
Contrary to what its name suggests, a blue moon is not actually blue in colour.
It simply refers to the frequency or the appearance of a second full moon in a single month.
A moon’s complete cycle typically takes around 29 days and most months are longer at 30 or 31 days, which is why it’s rare for two supermoons to appear in the sky in the same month — hence the saying, “once in a blue moon.”
As the cycle of the phases of the moon lasts approximately one month, we typically experience 12 full moons each year.
Many cultures have given distinct names to each month's full moon. 12 months, 12 full moons, 12 names.
Simple right?
Well, not quite.
Well, not quite.
Here's where the Blue Moon comes into the equation.
The moon phases actually take 29.5 days to complete which means it takes just 354 days to complete 12 lunar cycles.
The moon phases actually take 29.5 days to complete which means it takes just 354 days to complete 12 lunar cycles.
So every 2.5 years or so a 13th full moon is observed within a calendar year.
This 13th full moon doesn't conform to the normal naming scheme and is referred to as the Blue Moon.
Contrary to the popular phrase "once in a blue moon", Blue Moons can occur relatively frequently, that is, in astronomical terms.
Blue Moons occur once every two to three years, according to NASA.
As there are roughly 29.5 days between full moons, February will never experience a monthly Blue Moon as it only has 28 days in a common year and 29 in a leap year.
What is a supermoon?
A supermoon occurs when the moon’s orbit is closest to Earth, at the same time it is full; astronomers call this ‘perigee’. According to astrologer Richard Nolle, who also coined the term, a full moon or new moon is a supermoon when it’s also within 90% of its closest point to Earth.
What is a supermoon?
A supermoon occurs when the moon’s orbit is closest to Earth, at the same time it is full; astronomers call this ‘perigee’. According to astrologer Richard Nolle, who also coined the term, a full moon or new moon is a supermoon when it’s also within 90% of its closest point to Earth.
This simply means the moon is substantially brighter and larger than usual.
When can you see the supermoons in Australia?
The supermoon or blue moon will appear in our skies around 11.36am AEST on Thursday, August 31.
As such, the blue moon will roll into Sydney’s celestial airspace at midday on August 31, 2023.
The supermoon or blue moon will appear in our skies around 11.36am AEST on Thursday, August 31.
As such, the blue moon will roll into Sydney’s celestial airspace at midday on August 31, 2023.
This moon will reportedly be the biggest moon of the year, and will probably also be pretty spectacularly bright. We imagine the best time to see it will be at dusk on Thursday, so make sure you take yourself to an excellent viewing point.
