why does the moon look so big

The Moon looks so big sometimes because of a well-known optical illusion called the "Moon illusion." When the Moon is near the horizon, the brain misinterprets its size, making it appear larger than when it is high up in the sky. This illusion occurs because the brain compares the Moon's size to nearby objects on the horizon, such as trees or buildings, which provide a sense of scale. When the Moon is high in the sky, lacking such reference points, it appears smaller to the observer. Importantly, the Moon's actual size and distance don't significantly change between these positions; photographs show the Moon's size remains the same regardless of its elevation in the sky. The illusion is rooted in how the brain processes visual information and perceives distance and size in the context of the sky and landscape, rather than any physical change in the Moon itself or atmospheric magnification. Various theories explain this phenomenon, including the brain perceiving the sky as a flattened dome and thus interpreting the horizon Moon as farther away and larger. However, the exact cause remains a topic of scientific discussion without a definitive explanation.