Have you ever looked up at the sky and noticed two bright spots on either side of the sun? If so, you might have seen parhelia, also known as sun dogs. These dazzling optical phenomena are a fascinating and rare sight that have puzzled people for centuries. In this article, we’ll take a closer look at what parhelia are, how they form, and why they’re so special.

Parhelia are halos of light that appear on the same horizontal plane as the sun, at an angle of about 22 degrees. They are caused by the refraction of sunlight by ice crystals in the upper atmosphere, which splits the light into different colors and creates a halo around the sun. Sometimes, the ice crystals align in a way that produces two bright spots that flank the sun, creating the illusion of three suns in the sky. These spots are usually reddish or yellowish and may be surrounded by a faint halo or veil.

The name “parhelia” comes from the Greek words “para” (beside) and “helios” (sun), reflecting the fact that these bright spots are always located at the same distance from the sun, but on opposite sides. They are also called “sun dogs” because they follow the sun like faithful pets. Different cultures have attached different meanings and legends to parhelia. For example, some Native American tribes saw them as omens of war or famine, while others considered them as signs of good hunting or weather. In medieval Europe, parhelia were sometimes interpreted as celestial signs of divine approval or disapproval.

Although parhelia are not rare, they are not always visible, as their appearance depends on several factors, such as the position of the sun, the height and orientation of the ice crystals, the clarity of the sky, and the observer’s location and angle of view. They are more likely to occur in colder and drier climates, such as the Arctic or the Antarctic, where there are more ice crystals in the air. They can also be seen in mid-latitude regions, such as North America, Europe, or Asia, during certain times of the year, when the sun is low in the sky and the air is clear and dry. However, even in ideal conditions, parhelia are fleeting and may last only for a few minutes or even seconds.

Despite their brief appearances, parhelia have captured the imaginations of people throughout history and have inspired many works of art, literature, and music. They have also been studied by scientists and researchers to learn more about the properties of light, ice, and the atmosphere. Parhelia can reveal information about the size, shape, and orientation of ice crystals, which can affect the colors and shapes of the halo and the spots. They can also help to monitor the concentration and distribution of atmospheric pollutants, such as volcanic ash, dust, or smoke, which can have significant effects on air quality and climate.

parhelia are a stunning and rare sight that have captivated people for centuries. Although they are caused by scientific principles, they have also been imbued with cultural and spiritual meanings that reflect our human connection to the sky and nature. Whether you see them as omens, guardians, or companions, parhelia are a reminder of the beauty and mystery of our world.