Though we see the rainbow as an arch, the funny thing is it’s actually a circle. It’s just that we don’t see the other half as we cannot see the water droplets in the air below the earth’s horizon. As we move to higher grounds, the arch of the rainbow gets higher as well. It is possible to view a rainbow from an airplane as well! From there it looks like a complete circle as you can see the water drops which are below the horizon as well as those above it. What’s more, you will also see the shadow of the airplane in the center!