Sunday, on our way home from camping, we stopped to pick up Thai food, and from the parking lot of the restaurant, spied this pair of sun dogs flanking the sun.
Later that evening, as we sat down on the deck to eat, we could still see one sun dog (the other one blocked by the house), and part of a halo around the sun (and, possibly, as second halo around that one).
And above that, an upside-down rainbow.
From The Cloud Collector's Handbook, we learned that the rainbow smile is actually a circumzenithal arc. All three phenomena occur when sunlight is refracted through ice crystals of high, thin clouds. My meteorologist friend says he's only every seen one circumzenital arc, so we're pretty lucky to have been smiled down upon by this rainbow.