You don't see this every sunset

[W.G.Ewald]

It pays to look up every now and then by Andrew Malcolm - Investors.com

These are polar mesospheric clouds, which appear on certain days about this time of year. These thin, feathery-like clouds occur when sufficient water vapor accumulates and freezes into ice crystals between 47 and 53 miles altitude.

Light beams from a setting sun just over the horizon reach back to eerily illuminate the crystals starkly against the intense blackness of deep space. They've been dubbed "night-shining clouds.."