When Jessica Lee, astronomer at Royal Observatory Greenwich announced that the October 2025 SupermoonUnited Kingdom will peak at 6:20 PM BST on Tuesday, October 7, the country’s sky will host the first supermoon of the year, astronomers and casual sky‑watchers alike are bracing for a night‑long light show.
What Makes This Full Moon a Supermoon?
A supermoon isn’t magic; it’s simply the full moon aligning with the Moon’s perigee – the point where its elliptical orbit brings it closest to Earth. In October 2025 the lunar distance will shrink to roughly 356,500 km, compared with a typical apogee distance of about 405,500 km. That 12‑percent reduction translates into a Moon that can appear up to 14 percent larger and 30 percent brighter than a “regular” full moon.
The effect is most noticeable when the Moon is low on the horizon, where the classic “moon illusion” tricks our brain into seeing it even bigger. Scientists have measured the apparent diameter at about 33 arc minutes for this event, versus the average 31 arc minutes.
When and Where to Look: Timing and Visibility
Because October days are already shortening, the Moon will rise just after sunset – around 6:00 PM – and won’t set until roughly 9:00 AM the next morning. That gives a 15‑hour window for anyone commuting, walking the dog, or simply sipping evening tea to catch the glow.
- Rise: 18:00 BST (October 7)
- Peak illumination: 18:20 BST
- Set: 09:00 BST (October 8)
For viewers in Greenwich, London, the moon will arc high over the Thames, making the cityscape an even richer foreground.
Expert Insight from the Royal Observatory Greenwich
Lee explains, "A supermoon occurs because the Moon's orbit around the Earth isn’t a perfect circle. Sometimes it's a bit closer to us and appears slightly bigger, sometimes it's farther away and appears slightly smaller – that’s what we call a ‘micromoon.’" She adds, "You can see it at any time and from any place, without specialist equipment, as long as you have a clear view of the sky."
She also cautions about light pollution: “If you’re in a densely lit area, try stepping back a few streets or heading to a park. The contrast makes the Moon’s colour and craters pop.”
The Moon Illusion and How to Experience It
During the early evening, when the Moon hovers just above the city’s rooftops, the "moon illusion" hits its stride. Lee describes it: "When the Moon appears near trees or buildings, our brain interprets the distance cues and inflates its size in our perception. It feels like the Moon is teasing us from the horizon, even though its angular size hasn’t changed."
To make the most of it, set up a phone camera with a simple zoom, line up a familiar landmark, and watch the Moon’s apparent size shift as you move farther away.
Astrological Meaning and Cultural Traditions
While astronomers stick to physics, many astrologers see October’s full moon in Aries as a karmic turning point. The lunar chart forms a trine aspect to asteroid Vesta, which they interpret as a boost to personal dedication and inner fire.
Historically, this phase is also known as the Harvest Moon or Hunter’s Moon. In medieval Europe, the extra evening light helped farmers finish grain threshing and gave hunters a longer glow to track game. That practical legacy still resonates in rural UK festivals that now blend music, food stalls, and telescope‑watching parties.
Looking Ahead: The 2025 Supermoon Series
October’s spectacle kicks off a trio of supermoons slated for the rest of the year. The next one lands on November 5, followed by the final 2025 supermoon on December 4. Each will occur at perigee, but the October event enjoys the added bonus of a higher autumnal horizon, which generally means clearer, steadier skies.
For educators, the series offers a perfect timeline to teach orbital mechanics, light reflection, and cultural astronomy in one package. Museums across the UK are already planning night‑time workshops, and several universities have pledged to livestream the December supermoon for a global audience.
Frequently Asked Questions
How bright will the October 2025 supermoon appear compared to a regular full moon?
Scientists estimate the supermoon will be about 30 percent brighter than a typical full moon, thanks to its closer distance of roughly 356,500 km. The increased brightness makes lunar surface details, like crater shadows, easier to spot without a telescope.
Do I need any special equipment to view the supermoon?
Not at all. The supermoon is visible to the naked eye from any location with a clear sky. A pair of binoculars or a modest telescope will enhance the view, but even a smartphone camera can capture the enlarged disc if you frame it against familiar landmarks.
Why is this moon called the Harvest Moon?
The term dates back to agrarian societies that relied on moonlight to finish harvesting crops before winter. In the Northern Hemisphere, the full moon closest to the autumnal equinox traditionally provided extra evening illumination, hence the name.
What is the "moon illusion" and how can I see it?
The moon illusion is a psychological effect where the Moon looks larger near the horizon than it does higher in the sky. To experience it, look for the Moon just after sunset with nearby trees, buildings, or a skyline as reference points – your brain will interpret the Moon as unusually large.
Will the later 2025 supermoons be as visible as the October one?
The November and December supermoons will also be at perigee, but the Moon will sit lower in the sky as we move deeper into winter, which can add atmospheric haze. Nevertheless, they’ll still be noticeably larger and brighter than average full moons, offering great viewing opportunities.
