Sundogs over Southern Mississippi
If you looked up in Monday afternoon's sky, you may have noticed a strange weather phenomenon. The sun appeared to have a halo and two bright spots on either side of it: this is called a sundog.

Sundogs occur when light interacts with ice crystals in the sky.

Thin and wispy cirrus clouds high in the sky are made up of ice crystals. And as the sun's light shines down through those ice crystals, the rays of light are bounced off of each ice crystal, forming unusual arcs of light on either side of the sun.

"Sundogs are best seen when the sun angle is low like just after sunrise or just before sunset," said WLOX First Alert Meteorologist Wesley Williams. "In each sundog, the colors typically are red closest to the sun, changing to blue on the outside of the sundog."
Southern Mississippi sundogs
This phenomenon is not limited to sunlight. Though rarer, it can also occur under moonlight and would be called a moondog.