The Circumzenithal Arc (CZA), often referred to as the “Smile in the Sky”,

 

The Circumzenithal Arc (CZA), often referred to as the “Smile in the Sky”, is one of the most spectacular natural light phenomena in the sky. Although it is relatively rare, whenever it appears, it captivates observers with its vivid colors and the characteristic “rainbow smile” high above. Among halo phenomena, the CZA stands out for its brightness and intensity, often surpassing other types of halos.

The CZA occurs when sunlight is refracted through horizontally oriented, plate-shaped ice crystals suspended in high-altitude clouds, such as Cirrus or Cirrostratus clouds. When these crystals are positioned just right, sunlight entering at a specific angle is bent upward, producing a colorful arc that curves overhead. From the ground, it appears like an “upside-down rainbow,” forming only about a quarter of a full circle rather than a complete arc.

Although it resembles a rainbow, the CZA differs fundamentally from a traditional rainbow, which forms when sunlight is reflected and refracted in water droplets after rainfall. In contrast, the CZA results from sunlight passing through ice crystals and is classified as a halo phenomenon. Typically, it appears in clear skies without rain, and its vivid colors are strikingly more intense than those of other halos.

The arc of a CZA is located on the same side as the sun but high above, near the zenith, requiring observers to tilt their heads upward to see it. Its color arrangement is also reversed compared to a rainbow: blue is on the inner edge (closer to the zenith), while red is on the outer edge (closer to the horizon).

Several precise conditions must be met for a CZA to appear:

• The sun must be lower than 32 degrees above the horizon.

• High-altitude clouds must contain an adequate number of plate-shaped ice crystals.

• The crystals must be oriented horizontally and remain stable.

Because these conditions are rare, the CZA does not appear frequently, making each sighting a special and memorable event for sky watchers and nature enthusiasts.

In summary, the Circumzenithal Arc is a beautiful, simple phenomenon that showcases the wonder of natural physics. It is truly a “smile in the sky,” formed by the perfect alignment of sunlight, ice crystals, and atmospheric conditions.

The Blobfish “the world’s ugliest fish.”

 

The Blobfish (scientific name: Psychrolutes marcidus) is a deep-sea fish famous for its bizarre appearance, earning it the title of “the world’s ugliest fish.”

🐡 Blobfish have soft, jelly-like bodies — a special adaptation that allows them to stay buoyant under the extreme water pressure of the deep sea. Their skin lacks scales, making it delicate and fragile.

🐡 When brought to the surface where the pressure is far lower, their bodies lose structure and expand, turning into the “melting jelly blob” with a big nose and droopy face that most people recognize. However, in their natural deep-sea habitat, they actually look much more like a regular fish.

🐡 Blobfish grow to about 30 centimeters in length and weigh around 1–2 kilograms.

Unlike most fish that live closer to the surface, blobfish lack a swim bladder — an organ that normally helps control buoyancy — because it would burst under the immense deep-sea pressure. Instead, their gelatinous bodies, being less dense than seawater, allow them to float just above the ocean floor.

They inhabit depths between 600 and 1,200 meters, where the pressure can be over 100 times greater than at sea level. Blobfish are found mainly off the coasts of mainland Australia, Tasmania, and New Zealand.

Because they have very little muscle, blobfish move extremely slowly, conserving energy by simply drifting near the seabed. They are sit-and-wait predators, feeding on small crustaceans like crabs, shrimp, and shellfish, as well as slow-moving creatures such as sea snails and starfish. When prey drifts close enough, they simply suck it in whole, since they have no teeth.