The first supermoon of 2025 is set to light up the night sky this week, kicking off a trio of spectacular lunar events before the end of the year.

October’s full Harvest Moon in 2025 will be both the largest and brightest full moon so far this year, and the first supermoon since late 2024. It marks the beginning of three consecutive supermoons expected from now until December.

What Makes a Supermoon Super?

The supermoon's meaning comes down to distance. Because the moon orbits the earth in an oval-shaped path, it sometimes comes closer than usual. 

So, when the full moon appears near this closest point (known as perigee), it looks slightly larger and brighter to the naked eye.

In astronomical terms, a supermoon occurs when a full moon happens within 90% of its nearest approach to the earth. The difference may sound small, but it can make the moon appear up to 14% bigger and nearly a third brighter than usual.

Why It’s Called the Harvest Moon

Every full moon of the year has a traditional name tied to the rhythms of nature. The Harvest Moon of 2025 takes its title from its proximity to the autumn equinox, when farmers once relied on its extended light to gather crops after sunset.

The Harvest Moon will rise close to sunset for several evenings in a row, bathing the earth in extra light. Its golden hue and long history have made it one of the most beloved moons of the year, often celebrated in music, art, and folklore.

What to Expect from October’s Supermoon

This October supermoon will be especially bright because it coincides with the moon’s closest point to the earth. Sky watchers will be expecting a large, luminous disc that glows warmer near the horizon before shifting to a whiter light as it climbs higher in the sky. 

And the reddish or orange tint that often appears early in the evening isn’t just an illusion, either. It happens because the moon’s light is passing through more of the earth’s atmosphere when it’s low in the sky, scattering blue wavelengths and allowing the warmer tones to shine through.

The Moon Illusion Explained

Now, if the Moon seems enormous as it rises, that’s your brain playing tricks on you. Known as the “moon illusion,” this optical effect occurs because we perceive the moon in relation to nearby objects like trees or buildings. 

Even though its actual size doesn’t change, the contrast makes it appear much larger on the horizon than when it’s overhead.

Scientists have long studied this illusion, but the exact cause remains uncertain. The consistent beauty of the effect, however, never fails to capture our attention every time a supermoon appears.

More Supermoons Still to Come

The first supermoon of 2025 won’t be the last. Two more are expected before the year ends, creating a rare trio of bright lunar displays to close out 2025.

What’s nice is that each supermoon gives us a moment to pause and look up, a reminder of how even familiar sights like the moon can still inspire wonder when seen in a bright new light.