Yep, it was spectacular seeing that circular
rainbow. I didn't have the best camera in the world, so this is
the best we could do. You can see the rainbow sweeps from 7:00 to
5:00 and the conical peak of Mt. Wilhelm is very clearly visible.
If you look closely, there is a subtle vertical shadow in the middle of
the rainbow, this is...Thomas and I! If you look even more
closely, you can see a second rainbow surrounding the main one.
This double-rainbow occurs under certain conditions, but isn't
always present.
If
you measure various aspects of the rainbow in terms of size and angles,
you can actually calculate the size of the water droplets in the cloud
in microns (millionths of a meter). I have to confess, I haven't
done this yet. It doesn't matter, seeing this upon the tops of
the clouds was one of the greatest things I've ever seen.