Interesting Facts About Sundogs

Have you ever spotted a bright spot of light next to the sun, with vibrant colors like red and blue? Those dazzling displays are called sundogs, and they’re a fascinating natural phenomenon caused by the way sunlight interacts with ice crystals in the atmosphere. Here’s the science behind sundogs, how to identify them, and interesting facts about these colorful illusions.

How Sundogs Form

Sundogs appear when sunlight refracts (bends) through tiny, hexagonal ice crystals suspended in high-altitude cirrus clouds. These crystals act like prisms, splitting sunlight into its different colors, similar to a rainbow.

The specific angle of the ice crystals determines the colors we see in a sundog. The red light bends the least, appearing closest to the sun, while the blue light bends the most, forming the outer edge.

Identifying Sundogs

Sundogs typically appear at around 22 degrees to the left or right of the sun. They often come in pairs, one on each side, and are most easily spotted when the sun is low in the sky, such as during sunrise or sunset.

Here are some key features to help you identify a sundog:

• Position: Approximately 22 degrees from the sun, usually in pairs.
• Color: Reddish tint closer to the sun, transitioning to blue or white on the outer edge.
• Shape: Often appears as a bright spot or patch of light.

Interesting Facts About Sundogs

• Frequency: Despite requiring specific conditions, sundogs are relatively common, sometimes appearing as often as twice a week.
• Visibility: They can be seen anywhere in the world, even near sea level, as long as cirrus clouds are present.
• Color Spectrum: The red light bends the least, appearing closest to the sun, while the blue light bends the most, forming the outer edge. This creates a beautiful spectrum with a reddish tint near the sun, transitioning to blue or white on the outer edge.
• Companion Phenomenon: Sundogs are not alone! Sun halos, those captivating rings of light surrounding the sun, are also formed by the refraction of sunlight through ice crystals.
• Scientific Name: The scientific term for sundog is “parhelion,” which comes from the Greek word meaning “beside the sun.”
• Sundogs have been referenced in various cultures and even inspired works of art.
• The band Rush mentions this phenomenon in their 1989 song “Chain Lightning.”

By understanding the science behind sundogs, you can appreciate these beautiful displays of light the next time you spot them in the sky!