With the sun setting early, July is giving us a reason to look up – there's a supermoon coming, and it's the biggest one of the year.
For those of us who don't enjoy being outside in the middle of a shivering winter's night, Thursday evening is one of the best chances to catch a glimpse of July's 'Buck' moon.
When can I see the Buck supermoon in Australia?
The Buck moon will reach its peak on Thursday, July 14, around 4:37am AEST. But there's no need to set your alarm.
NASA says the moon will appear from early Thursday morning through to early Friday morning, giving you plenty of viewing opportunity.
What's the best time to see it?
The University of Queensland's Dr Benjamin Pope says, "anytime after dark, it should be visible."
For the clearest views of the moon, NASA recommends avoiding areas surrounded by tall buildings and thick forestry.
Why is it called 'Buck' and what makes it a supermoon?
July's Buck moon derives from the Native American Algonquin tribes who first published its name in the Maine Farmer's Almanac in the 1930s.
It's a reference to the time of year when new antlers are growing on male deer, or bucks.
What makes it a supermoon is its close proximity to earth, or perigee.
Dr Pope says the moon's orbit around the earth is not perfectly circular, and perigee is what we call the point of closest approach.
NASA says when a full moon appears at perigee, it is larger than a regular full moon.
What is a supermoon?
The term supermoon was originally coined by an astrologer Richard Nolle in 1979.
Nolle defined a supermoon as being any full moon that takes place within 90 per cent of its closest approach to earth.
However, there have been a number of definitions of a supermoon.
Some say a supermoon is any full or new moon that occurs within 24 hours of it making its closest approach to Earth that month.
Others say it's when the full moon comes within 360,000 kilometres of Earth.
This moon meets both those definitions, but either won't change your view much.
Is it all just an illusion?
While this month's full moon will be closer to earth, it won't actually look noticeably bigger to many.
"The difference between a supermoon and an 'ordinary' full moon is barely perceptible to the naked eye," Dr Pope says.
However, if you look at it near a horizon or next to a building, it will look 'super' thanks to something called the moon illusion – a visual trick our brains play on us.
When you observe the moon while its close to the horizon, your perspective is actually being altered, making the moon appear larger.
What other supermoons are there? When do they occur?
A supermoon forms several times a year, when the moon is at its observable brightest, which we can predict by knowing the speed and geometry of the earth, the sun and the moon.
There's a few interesting names given to supermoons. Here's what they are, by the month:
- January: Wolf moon
- February: Snow moon
- March: Worm moon
- April: Pink moon
- May: Flower moon
- June: Strawberry moon
- July: Buck moon
- August: Sturgeon moon
- September: Harvest moon
- October: Hunter's moon
- November: Beaver moon
- December: Cold moon
More celestial spectacles to come this year
Supermoons are pretty common.
Depending upon your definition, there are between two and four supermoons a year.
July's Buck moon comes after the Strawberry moon, which peaked on June 14, marking the second supermoon of 2022. But there's one more to come.
August’s full Sturgeon moon reaches its peak on August 11 and will be the last supermoon of the year.
But to really finish the year off with a bang, a total lunar eclipse will be visible for Australia on November 8.
