Sundogs are two bright spots on opposite sides of the sun, creating the optical effect of three suns. They're usually incorporated within a halo and are sometimes associated with an approaching frontal system too. Sundogs are formed when light is refracted, or bent, by ice crystals in cirrus clouds. The ice crystals must be aligned vertically for sundogs to form. Moondogs are even more rare then sundogs, but both of them can occur all year long.
Auroras appear to be like luminous curtains of multicolored light draping over the night sky.
Auroras are formed when charged solar particles collide with gas molecules in the earth's atmosphere and produce bursts of visible light. This phenomenon is known as the aurora borealis in the Northern Hemisphere and the aurora australis in the Southern Hemisphere. However, the borealis has been seen as far south as Mexico City and the australis has been seen as far north as Brisbane, Australia. Auroras are especially unique because they can actually be hazardous. They disrupt radio communications, because they create static.