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 ...

A mysterious spiraling blue light illuminated the night skies over Europe on Monday.The cosmic whirlpool was captured in ...

A weird blue spiral of light, captured on photo in the night sky? As much as we might want it to be, we know by now that it's not aliens (it's never aliens, OK?). But little green men aside ...