The moon also rises—and assumes new sizes

People have long noted that a full moon seems to shrink and expand in size depending on its heavenly position. A moon looks larger near the horizon than perched high in the sky, although its distance from Earth remains the same.

Scientists have yet to unravel the so-called moon illusion. Experiments now indicate that a horizon moon grows larger because it lies near visual markers of depth and distance on Earth’s landscape that make it look much farther away than a higher moon.