Sundogs Like light pillars, sundogs are the product of light passing through crystals. The particular shape and orientation of the crystals can have a drastic visual impact for the viewer, producing a longer tail and changing the range of colors one sees. The relative height of the sun in the sky shifts the distance the sundogs appear to be on either side of the sun. Varying climactic conditions on other planets in our solar system produce halos with up to four sundogs from those planets' perspectives. Sundogs have been speculated about and discussed since ancient times and written records describing the various attributes of our sun date back the Egyptians and Greeks.