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Moon Illusion

Why the Moon Looks Huge on the Horizon

The Moon rising over the rooftops looks enormous, yet at arm's length it measures the same as when it's high in the sky, and it's actually about 1.5% farther away. Scientists still debate why your brain blows it up.

Sources (3)
  1. NASA Science, "The Moon Illusion: Why Does the Moon Look So Big Sometimes?" (opens in a new tab)
  2. L. Kaufman & J. H. Kaufman, "Explaining the moon illusion", PNAS 97 (2000) (opens in a new tab)
  3. Wikipedia, "Moon illusion" (opens in a new tab)

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