A luminous column of light, known as a solar pillar, appears above the sun during sunset, caused by ice crystals reflecting sunlight.
Solar pillar observed during sunset
A luminous column of light rising above the sun during sunset has been observed, a phenomenon known as a solar pillar. This optical effect occurs when light from the sun is reflected by plate-shaped ice crystals suspended in the atmosphere.Optical phenomenon explained
According to meteorological sources, solar pillars are classified among halos—optical effects that appear around the sun or moon due to the refraction and reflection of light by ice crystals. The formation of these vertical streaks requires specific atmospheric conditions, including the presence of fine, plate-shaped ice crystals, often found in high cirrostratus clouds.Conditions for visibility
The National Weather Service notes that solar pillars are particularly visible when the sun is less than 6 degrees from the horizon, which is why they are more frequently observed during sunrise and sunset. There are two types of pillars: upper pillars, which appear when the sun or moon is low and the light reflects off the bottom of the crystals, and lower pillars, which form when the crystals are below the observer.Examples and distinctions
NASA has documented instances of this phenomenon, including an image captured in Mohe, the northernmost city in China, where luminous pillars were seen alongside the constellation of Orion in a glacial sky. It is important to distinguish solar pillars from other light illusions such as auroras or artificial spotlights. Unlike auroras, solar pillars are not caused by charged particles in the atmosphere but by the reflection of light on ice crystals.How to spot a solar pillar
To recognize a solar pillar, look for a thin, elongated vertical shape directly above or below the sun, typically observed during late afternoon or early morning in cold weather or when ice clouds are present. With the return of winter time, sunsets occur earlier, increasing the likelihood of observing this natural phenomenon. No special equipment is required to view this spectacle, only a clear sky and low temperatures.
