The supermoon to rise into the Thursday night sky will be the brightest of the year, experts say, rivalled only by a comet dubbed “the best of the decade” so far.
The October full moon, also known as the hunter’s moon, will be the third of four back-to-back supermoons, preceded by September’s harvest moon and August’s blue supermoon. November’s beaver moon is still to come.
Dr Brad Tucker, an astrophysicist from the Australian National University, explains the full moon names often come from those given to them in North America by the Farmer’s Almanac and Native Americans because, like many cultures, they regulated themselves through the lunar cycle.
In the case of the hunter’s moon, it coincides with the time of year approaching winter since “your last chance at going out and hunting for food is really this month”, Tucker said.
So what is it and how can Australians see it?
What are supermoons and why have they come in series?
A supermoon occurs when a full moon coincides with when the moon is at perigee, the closest point to the Earth, Tucker explained.
That’s because the moon’s orbit is not a perfect circle around the Earth – but rather varies by about 10% in relation to our planet.
“Closer to the Earth, relative to us in the sky, it looks bigger and it’s reflecting more sunlight to the Earth – we see the moon because it’s reflected sunlight – and therefore brighter.”
Supermoons can occur in a series “because what’s going on is the orbit of the moon wobbles”, Tucker said. “It’s kind of like a top spinning – and you sometimes get the wobbles in sync, happening every cycle.”
What makes the hunter’s moon special?
It will be brightest supermoon of the year, according to Prof Jonti Horner from the University of Southern Queensland because the Earth has moved slightly closer to the sun in October since September.
While the Earth will be closer yet to the sun the next supermoon in November, the distance between the Earth and moon will not be quite as close, and that is what ultimately matters when it comes to the brightness.
Ultimately though it is a bit of a “moot point”, Horner said, because the human eye will not be able to perceive these changes in brightness.
What’s the best way to see it from Australia?
“The full moon – whether a normal moon or supermoon – is always best seen at moon rise, which is the same time as sunset,” Tucker said.
Sunset can depend on your location, however, so moon watchers should check the time in their local area. It’s likely to take place about 7.45pm at this time of year.
Moon watchers will see what is known as the “moon illusion” or “the Orion illusion”, Tucker said.
“You get to the effects of the atmosphere rising as well as the optical illusion effects of your eyes seeing the moon with respect to other things.”
Is there anything else people should look out for?
Horner adds that while people are looking at the sky they should keep their eyes out for the “best comet of the decade so far”.
“If people are out looking at the moon at 6.30pm or 7pm, they should then spin around and look to the west. The first thing they’ll see there is Venus, bright as an aircraft coming in with its headlights on. That’s awesome enough but to the right of that and a bit lower is comet C/2023 A3 (Tsuchinshan-ATLAS) – the best comet of the decade so far,” Horner said.
Although it has begun to fade, it’ll still be visible with the naked eye – even moreso with a camera or binoculars, he added.
“And if you don’t see it in the next few days you’ll never see it because once it is gone, it’ll never return,” Horner said.
