Sun dog

Sometimes you see extra suns in the sky.

They look like bright spots. They sit beside the real sun. These spots come from tiny ice.

The ice is shaped like flat plates. These plates bend the light. This makes the bright spots appear. They can have soft colors too. You might see red or blue.

You can see them anywhere in the world. It is a fun sight. Have you seen them?

Have you ever seen extra suns in the sky? These bright spots are called sun dogs. Scientists call them parhelia. They appear as bright patches of light. They sit on both sides of the sun.

Sun dogs happen because of ice crystals in the air. These crystals are shaped like flat plates. They float in cold clouds.

As they fall, they stay flat. This happens because they are horizontal. When sunlight hits these plates, it bends. This is called refraction. The crystals act like tiny prisms.

Sun dogs often show soft colors. The side closest to the sun looks red. The colors then change to orange and blue. You might also see a ring around the sun. This is a 22° halo. It can connect the sun dogs together.

You can see sun dogs anywhere in the world. They are easiest to see when the sun is near the horizon.

Have you ever looked at the sky and seen extra suns? These bright spots are called sun dogs. Scientists use the formal name parhelia to describe them. They appear as bright patches of light on both sides of the sun.

Sun dogs are part of a larger family of ice halos. They are often seen as a pair of colored patches. These patches sit about 22 degrees to the left and right of the sun. They usually stay at the same height as the sun itself.

Sun dogs happen because of how light moves through ice. Tiny ice crystals float in cold clouds or freezing air. These crystals have a flat, six-sided shape called a hexagon. They fall through the air with their flat faces pointing sideways. When sunlight hits these crystals, the light bends. This bending is called refraction. The crystals act like tiny prisms to redirect the light.

Larger crystals wobble more as they fall. This wobble can make the sun dogs look taller. The colors start as red near the sun. They then fade into orange and blue further away.

People have noticed these lights for a very long time. The Greek thinker Aristotle wrote about mock suns in ancient times. He noted they stay to the side of the sun. In the 1500s, a painting in Stockholm showed a large halo display. This famous work is called the Sun Dog Painting. It was made to record a strange sky over the city in 1535.

Later, in 1629, Pierre Gassendi explained how the light reflects off ice. This helped people understand the science behind the beauty.

There are many interesting facts about these light shows. You can see sun dogs anywhere in the world. They are easiest to spot when the sun is near the horizon. Sometimes, a ring called a 22 degree halo connects the sun dogs. In 1843, people in Newfoundland saw them during a very cold winter. They called them sun dogs to warn of coming blizzards. Even other planets might have them. Mars could have sun dogs made of water ice or carbon dioxide ice. Giant planets like Jupiter might have even more sun dogs.

Sun dogs help us understand how light and ice work together. They are like a natural light show in the atmosphere. You might see them alongside other shapes like the circumzenithal arc. That arc is a colorful band located directly overhead.

When the sun rises higher, the sun dogs move farther away from the halo. This happens because the light hits the crystals at a different angle. Next time you see a bright spot in a cold sky, look closely. You might be watching a parhelion in action.

A sun dog, or parhelion, is a striking atmospheric optical phenomenon. It appears as one or two bright spots of light located beside the Sun. These spots are part of a larger family of ice halos. Halos are patterns of light created when sunlight interacts with ice crystals in the atmosphere.

While many people use the term "sun dog" to describe any halo, parhelia are a specific type. They are most noticeable when the Sun is positioned near the horizon.

The formation of sun dogs relies on the physics of refraction. Refraction is the bending of light as it passes from one substance into another. This process occurs when sunlight hits hexagonal, plate-shaped ice crystals. These crystals are often found in high, cold cirrus clouds or cirrostratus clouds. They can also drift in freezing, moist air at low levels as diamond dust.

As these flat crystals fall, they tend to orient themselves horizontally. They act like tiny prisms, bending the sunlight with a minimum deflection of 22 degrees. This bending redirects the light to the left and right of the Sun.

Sun dogs have distinct visual characteristics and can appear in different forms. They typically look like colorful patches of light located about 22 degrees from the Sun. The colors are not pure or saturated, but they do show a specific gradient. The side of the sun dog nearest the Sun appears red. As you look further away from the Sun, the colors transition through orange and into blue.

The height of the sun dog can change based on the size of the crystals. Larger plates tend to wobble more as they descend, which produces taller sun dogs.

These phenomena are often seen alongside other atmospheric light displays. A 22° halo is a ring of light that forms at a similar angular distance from the Sun. This ring often appears to interconnect the two sun dogs.

Another related feature is the circumzenithal arc. This is a colorful arc located almost directly overhead. Because of its position, viewers often miss it while looking at the sun dogs. The colors of the sun dogs may eventually merge into the white light of a parhelic circle.

Humans have observed and recorded sun dogs for thousands of years. The Greek philosopher Aristotle noted "mock suns" in his writings on meteorology. He observed that these lights followed the Sun from sunrise to sunset. In the 16th century, the "Sun Dog Painting" was created in Stockholm. This artwork documented a complex halo display from April 20, 1535.

Later, in 1629, Pierre Gassendi provided a correct scientific explanation. He realized the phenomenon was caused by sunlight reflecting off ice or snow crystals at high altitudes.

Sun dogs are not limited to Earth and can be predicted on other worlds. On Mars, sun dogs might form from both water-ice and carbon dioxide-ice crystals. The giant planets, including Jupiter, Saturn, Uranus, and Neptune, may host even more complex displays. In these massive atmospheres, clouds made of ammonia or methane can create halos with four or more sun dogs. This shows that the physics of light and ice is a universal concept.

Understanding sun dogs helps scientists study the composition of the atmosphere. The way light bends tells us about the shape and orientation of ice crystals. As the Sun rises higher in the sky, the angle of the light changes. This causes the sun dogs to move farther away from the 22° halo. They maintain the same elevation, but their horizontal distance from the Sun increases. This relationship between the Sun's position and the light's path is a key part of atmospheric science.