A NEON SPIRAL AT SUNSET

 A NEON SPIRAL AT SUNSET 

Just after the sun slipped below the horizon, a glowing band of color curved across the twilight sky, blending pink, teal, gold, and violet into one smooth, twisting streak.

Scenes like this can happen when thin clouds at high altitude catch the last low-angle sunlight. Tiny droplets or ice crystals scatter and diffract the light, separating it into soft spectrum colors. Wind patterns stretch the cloud into curved shapes, making the color band appear to swirl.

What you’re likely seeing is a high-altitude contrail catching the last sunlight. When an aircraft passes at very high altitude during sunset, its vapor trail can stay illuminated long after the ground is dark. Ice crystals inside the trail scatter light, sometimes producing iridescent colors similar to those seen in thin clouds near the sun.

Wind shear up high can twist and stretch the contrail into spirals and waves, turning a straight line into a glowing sky-ribbon.

 Effects like this are often photographed over open landscapes in places like the North Dakota, Montana, and the Canadian Prairies, where wide horizons make twilight sky phenomena stand out.