According to Wikipedia, Twilight is the time between dawn and sunrise or between sunset and dusk, during which sunlight scattering in the upper atmosphere illuminates the lower atmosphere, and the surface of the earth is neither completely lit nor completely dark.

Also see : How to Search Google Using Images as Query

This was also what Google knew in 2004, however things have changed over years. If you googling for “Twilight” now, you will find totally a different set of pictures.

via: 9gag