Weird rainbow effect

While driving home today, I looked toward the west where the sun was on its way down (5:00pm EST) and to the left and right about a palm’s width from the sun, there was a small thumb-sized rainbow segment. The two segments stayed there until some clouds completely obscured the sun. Any ideas as to what would cause this sorta thing?

They’re called ‘sundogs’. and are pretty common if the climate is right - cold and clear. The cause is ice crystals high in the atmosphere that reflect the light much the same way that water droplets refract it in a rainbow. Because it’s reflection, they appear near the sun (at a fixed angle), instead of opposite.

Google returned this site, and many more:

http://antwrp.gsfc.nasa.gov/apod/ap990823.html

Add this to my “learn something new every day” file. That’s exactly what I saw. Thanks rjk!