Rainbows Are Actually Full Circles

A rainbow is always a complete circle, but the ground usually blocks the bottom half from our view. You would need to be in an airplane or on a high mountain to see the full ring of colors.

While we see rainbows as bows, the shape is determined by the spherical nature of water droplets. Because we stand on the ground, the horizon cuts off the circle before we can see the bottom. If you are ever high in the air when it rains, look down to catch the rare sight of a perfectly circular rainbow. You can also create your own miniature version by spraying a fine mist of water with your back to the sun.