Wow! That is extremely rare! What is this strange glowing X floating in the sky over the Gardermoen Oslo Airport in Norway? Is that a portal to another dimension? This strange atmospheric phenomenon is called an Antisolar Arc… And it is kind of out-of-this-world. Look by yourself:
According to photographer Tengesdal, the phenomenon was visible for less than 2 minutes. And as the plane moved out of the clouds the optical faded away.
This rare type of ice halo is called “anti-solar region arcs.” To see them, you have to stare directly away from the sun, looking down into icy clouds where subhorizon reflections from the faces of ice crystals create these strange arcs.
Anti-solar region arcs are bright but elusive, requiring a passenger to be seated in just the right spot, looking in just the right direction, at precisely the right moment as the plane ascends above icy clouds. Rare, indeed.