Why does the Moon appear larger when it's positioned near the horizon compared to when it's higher in the sky?

The phenomenon of the Moon appearing larger near the horizon remains an unsolved scientific mystery that has puzzled experts for over 2,000 years, dating back to Aristotle's observations. Despite extensive research and ongoing scientific experiments, there is still no definitive consensus on the exact cause of this optical illusion. While scientists have proposed various theories including atmospheric effects and the Ponzo illusion (a visual perception phenomenon), the complete explanation continues to elude researchers, making it one of astronomy's most enduring puzzles.