A supermoon in July 2022 | Elekes Andor, CC BY-SA 4.0 via Wikimedia Commons
By Margherita Bassi | Smithsonian Magazine
Earth’s skies are about to be graced with an out-of-this-world spectacle—literally. At 8:19 a.m. Eastern time this Wednesday, November 5, this month’s full “beaver” supermoon will reach its peak brightness.
Though the massive moon will be under the horizon for many United States viewers at its brightest moment, moon enthusiasts will be able to catch a look on Tuesday evening and Wednesday evening, when the moon will still appear full.
Because the natural satellite’s orbit around Earth isn’t perfectly circular, supermoons occur when a full moon coincides with the moon’s perigee—its closest point to the planet in its orbit, about 226,000 miles away.
November’s supermoon will be the second of three consecutive full supermoons this year. Sara Russell, a mineralogist and planetary scientist at London’s Natural History Museum, tells Sky News it will also be this year’s biggest—the closest supermoon of 2025.
Supermoons haven’t always been eagerly awaited: The term has only existed since 1979, when American astrologer Richard Nolle coined the term “supermoon” to describe a new or full moon taking place within 10 percent of its nearest point to Earth in its orbit. By that definition, we are experiencing eight supermoons this year—because five new supermoons occurred in earlier months. But now, the term is most often used to describe closer-than-usual full moons.
The idea of a supermoon also comes with some controversy. Per EarthSky’s Deborah Byrd and Marcy Curran, some astronomers don’t approve of the term and consider supermoons “hype” rather than a legitimate celestial phenomenon.
The supermoon on March 19, 2011, on the right, compared to the moon on December 20, 2010, on the left. | Images by Marco Langbroek, the Netherlands, using a Canon EOS 450D + Carl Zeiss Jena Sonnar MC 180mm lens / Marcoaliaslama, CC BY-SA 3.0 via Wikimedia Commons
While the term “supermoon” might lead some to expect a much larger moon in the sky, the size difference could be imperceptible, even to some experienced viewers. According to NASA, a supermoon appears about 7 percent larger than the average full moon and 14 percent larger than a full moon at its most distant point. The supermoon may indeed seem larger when it’s closer to the horizon, but that’s an optical illusion—the moon always looms large in that case. Instead, the most noticeable difference about a supermoon might be its brightness, per EarthSky—it appears about 16 percent brighter than an average full moon and about 30 percent brighter than the farthest full moons.
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