History buffs, astronomy enthusiasts and casual stargazers alike are all in for a treat this summer. The Harvest Moon will light up the sky on Tuesday, October 7th! It’s sure to be dazzling, too, as it will be a supermoon, marking the beginning of a supermoon trifecta this year. A supermoon occurs when a full or new moon coincides closely with the Moon’s closest approach to Earth, a point known as perigee. During this event, the Moon will be about 356,355 kilometers away, making it look brighter and larger than usual.
Supermoons never fail to dazzle us with their stunning splendor. Their beauty is a product of the intricate choreography of the Earth, Sun and Moon. It is these large celestial bodies that cause a wave-like pattern in subsequent full moon distances. Consequently, supermoons can happen consecutively over a handful of months before the alignment changes. In fact, the biggest supermoon is more than 14 percent larger than the smallest micro-moon. In reality, there’s actually an amazing 14 percent difference in size and a stunning 30 percent difference in brightness!
Understanding Supermoons
The unique alignment required for a full moon occurs when the Sun, Earth, and Moon are arranged in a straight line. Unfortunately for lunar observers, this ideal alignment does not perfectly match the Moon’s closest passage to Earth. The Moon’s orbit is slightly egg-shaped, causing it to drift closer or further away from Earth at different times throughout its cycle.
According to Jonti Horner, an astronomy professor at the University of Southern Queensland, supermoons are striking spectacles. He’s equally concerned with the more insidious things they do to our planet. “When the full moon is closest to the Earth, the full moon before and the full moon after are still a fair bit closer to the Earth than average,” he notes. This gravitational pull, while gentle, can still create subtle changes to ocean tides. It causes “spring tides,” not named for the season, but because they spring forth when the Moon’s pull is enough to lift water levels high.
When this month’s full moon – the Harvest Moon – rises into the sky, stargazers will be particularly thrilled. They’ll have two additional supermoons to anticipate this year, occurring in November and December. In a typical year, Professor Horner explains, we’ll get a succession of supermoons. This reality not only opens the door for amazing science, but it makes this an exciting time for enthusiasts of lunar phenomena!
The Illusion of Size
One of the coolest things about supermoons is the optical illusion we call the “Moon illusion.” When the Moon is low on the horizon at dusk, it appears disproportionately large. As it rises overhead, the apparent size seems to be shrinking. Though scientifically this is nothing more than an illusion, it contributes to the excitement of witnessing a supermoon.
If you’re excited to witness this month’s celestial spectacle, you’ve come to the right place. Professor Horner tells us that, “unlike the one we had in September, which was during morning rush hour, [this one] is ideal because it’s during evening rush hour. That’s for the exciting reason that millions more people will have the chance to look up and see the beautiful, bright orb that lights up the nighttime sky.
Professor Horner cautions that supermoons, while certainly impressive to behold, may not be as awe-inspiring as you’d think. No doubt they’re strikingly beautiful, but don’t let their appearance deceive you! He makes the case that if you looked at both one after the other, it would be very clear. He qualifies that it is not something that will cause you to stand up and cheer.
Looking Ahead
The excitement surrounding October’s Harvest Moon is just the start. Come the other months of this summer, the skies hold even more lunar magic, with two additional supermoons set to roll in. So save the date, astro-fans! In March 2026, a total lunar eclipse, or blood moon, will be viewable from every corner of Australia.
Residents of the U.S. won’t see another trifecta such as this year’s series of supermoons until 2033. It won’t be until November 25, 2026. The supermoon makes the Moon appear more massive than usual, a cosmic phenomenon that makes it particularly impressive to look at. In comparison, at its maximum distance from Earth, the Moon is about 406,725 kilometers, called apogee.
