A beam of light over an open field — it’s not the start of a sci-fi movie (in this case, at least). It’s what the sunset looked like in the Central Valley on Thursday.
But put away the tin foil hats. What everyone was seeing was a natural phenomenon called a sun pillar that occurs when the sun’s rays reflect off of ice crystals in the Earth’s atmosphere.
These tiny, flat crystals make up cirrostratus clouds (the thin, wispy ones). As they fall through the atmosphere, they create a vertical effect that makes the sun’s light look like a tractor beam.
Sun pillars are pretty common, according to Fresno State physics professor Frederick Ringwald.
“Notice how the temperature dropped during the past couple days, due to a cold front (a mass of cold air) passing over the Central Valley?” Ringwald said. “That's what formed the ice crystals, high up in Earth's atmosphere.”
Sun pillars typically happen around sunset, with the column of light growing taller after the sun goes down. And although they’re not rare, they make for a pretty cool photo, which explains the flood of sunset posts on Instagram.