The moon, like any celestial body, has a certain size and shape that is constant. Therefore, the moon cannot actually become “bigger” in a physical sense. However, the perception of the moon’s size can change due to various factors, including the moon’s position in its orbit around the Earth, the Earth’s position in its orbit around the Sun, and atmospheric conditions on Earth.
One factor that can contribute to the perception of a larger moon is the moon’s position in its orbit around the Earth. The moon’s orbit is not a perfect circle, but rather an ellipse, which means that the moon’s distance from the Earth can vary over the course of its orbit. When the moon is at its closest point to Earth, known as perigee, it can appear up to 14% larger and 30% brighter than when it is at its farthest point, known as apogee. This phenomenon is known as a “supermoon.”
Supermoons are relatively rare, occurring only a few times a year. When a supermoon coincides with a full moon, it can create a particularly impressive sight in the night sky. However, even a supermoon may not be noticeably larger to the naked eye, as the difference in apparent size between a supermoon and a regular full moon is only a few percentage points.
Another factor that can affect the perception of the moon’s size is the Earth’s position in its orbit around the Sun. The Earth’s orbit is also not a perfect circle, but rather an ellipse, which means that the Earth’s distance from the Sun can vary over the course of the year. When the Earth is closer to the Sun, known as perihelion, the gravitational pull of the Sun on the Earth is stronger, which can cause the Earth’s orbit to be slightly faster. This can lead to a situation where the moon appears to be closer to the Earth during certain times of the year, which can make it appear larger and brighter.
Atmospheric conditions on Earth can also affect the perception of the moon’s size. The moon appears larger when it is near the horizon because of an optical illusion known as the “moon illusion.” This illusion is caused by the way the brain processes visual information, and is not fully understood. One theory is that the moon appears larger near the horizon because of the presence of objects such as trees and buildings that provide a reference point for the brain to judge the size of the moon. When the moon is higher in the sky, there are no objects to provide a reference point, and the brain may perceive the moon as smaller.
In conclusion, the moon does not actually become physically larger, but its perceived size can change due to various factors such as its position in its orbit around the Earth, the Earth’s position in its orbit around the Sun, and atmospheric conditions on Earth. While a supermoon can create a particularly impressive sight in the night sky, the difference in apparent size between a supermoon and a regular full moon is only a few percentage points, and may not be noticeable to the naked eye.
