Skywatchers are preparing for a celestial event as the first and brightest supermoon of the year graces the night sky on the evening of October 6. The full moon will appear noticeably larger and more brilliant than usual, offering a spectacular sight for observers across the globe. This event marks the beginning of a series of three consecutive supermoons expected in 2025, providing multiple opportunities for lunar observation.
This October full moon, traditionally known as the Harvest Moon, coincides with its closest approach to Earth in its orbit, a point called perigee. This proximity, at a distance of approximately 224,600 miles (361,459 kilometers) from our planet, will cause it to look up to 14% larger and 30% brighter than when it is at its farthest point. The phenomenon, while observable with the naked eye, presents a unique opportunity for both amateur stargazers and seasoned photographers to capture its enhanced glow, especially as it rises near the horizon.
The Science of a Supermoon
The term “supermoon” describes a full moon that occurs at or near its perigee. The Moon’s orbit around the Earth is not a perfect circle but is instead elliptical, meaning its distance from our planet varies throughout its 27-day cycle. The point of closest approach is the perigee, while the most distant point is known as the apogee. A full moon at apogee is sometimes referred to as a micromoon.
While “supermoon” is a popular term, it is not a formal astronomical designation. Scientists and astronomers prefer the technical name “perigee-syzygy.” The term syzygy refers to the alignment of three celestial bodies, in this case, the Sun, Earth, and Moon, which is the alignment that produces a full moon. The name “supermoon” was first coined by an astrologer, Richard Nolle, in 1979 and has since been widely adopted in popular culture. Supermoons do not happen every month but tend to occur in groups of three or four in a row during certain parts of the year.
Effects on Earth’s Tides
The Moon’s gravitational pull is the primary force that creates Earth’s ocean tides. During a supermoon, when the Moon is closer to Earth, its gravitational force is slightly stronger, resulting in higher-than-usual tides. These amplified tides, sometimes called “king tides” or “supertides,” are a natural and predictable outcome of the lunar cycle. The alignment of the Sun, Earth, and Moon during a full moon already creates higher “spring tides,” and the Moon’s proximity during a supermoon enhances this effect.
The increase in tidal range is typically modest, often amounting to a difference of just a few inches compared to a normal spring tide. However, this heightened tidal effect can become more significant when combined with specific weather conditions. If a supermoon coincides with strong onshore winds or a coastal storm, the elevated sea levels can increase the risk of coastal flooding in low-lying areas. It is also worth noting that the highest tides often occur in the day or two following the exact moment of the full supermoon.
How to Best View the Event
A supermoon can be viewed by anyone without the need for a telescope or specialized equipment, provided the skies are clear. For the most visually impressive experience, observers should try to watch the moonrise shortly after sunset. When the Moon is low on the horizon, a phenomenon known as the “Moon illusion” makes it appear dramatically larger than when it is high in the sky. This optical illusion occurs because the brain compares the low-hanging Moon to familiar objects on the horizon, such as trees, buildings, or hills, creating a sense of grander scale.
To get the best view, it is advisable to find a location with a clear, unobstructed view of the horizon, away from the glare of city lights. Parks, fields, or waterfronts are often ideal spots. While the difference in apparent size can be subtle to a casual observer, the increased brightness is often more noticeable, casting a brilliant light across the landscape.
Photographing the Supermoon
Essential Equipment
For those looking to photograph the spectacle, a camera with manual settings and a sturdy tripod are essential to prevent blurring during exposure. While any camera can capture the event, a telephoto lens with a focal length between 400mm and 600mm is recommended to capture detailed close-ups of the lunar surface. Using a remote shutter release or your camera’s built-in timer will further minimize camera shake.
Camera Settings and Composition
A good starting point for camera settings follows the “looney 11” rule. Set the camera to manual mode, use an aperture of f/11, and match the shutter speed to the inverse of your ISO. For example, at a base ISO of 100, you would use a shutter speed of 1/100 of a second. These settings can be adjusted as needed until the image on your camera’s display looks correct. The best time to photograph is during the golden hour at moonrise or moonset, when the soft, colorful light of the sky allows you to capture both the Moon and the landscape in a single, well-exposed shot. Including foreground elements, such as a cityscape or a natural landmark, can add context and create a more compelling and dramatic image.
