A mysterious spiraling blue light illuminated the night ... shows the glowing light spinning across the sky in what many social media commentators likened to a spiral galaxy.

Complicated physics makes these molecules scatter more blue ... at sky brightness—what they call the sky background—they use a unit of brightness per area of the sky: how much light is spread ...

An unusual sight — a ribbon of glowing blue light — in the Dearborn sky that was posted Sunday on Facebook set off a round of jokes and speculation, including several references to ...