False Sun Over Cambridge

A "sun dog" over Cambridge, MA.

I was walking home one day when this view caught my eye. It's what's known as a false sun or "sun dog", and it happens when ice crystals in clouds act as a lens, and refract sunlight toward your eye. In this case, the glow in the clouds over the intersection is the false sun and the brighter glow over the building to the right is the real sun. More spectacular images still can be seen under exactly the right circumstances, making a full ring of light around the sun with bright spots to the left and right.

I've heard that under unusual circumstances including when volcanic ash is in the air, false suns can out-shine the real sun. I'd love to see something like that one day.