The green flash (photo above by TheBrockenInaGlory) has been seen at sunset by a few lucky people. Under the right conditions, the atmosphere behaves like a prism, separating the last solar light via refraction, so that the final trace of the Sun is green (blue light is scattered too much to be visible). This rare atmospheric phenomenon forms the backdrop to Jules Verne’s 1882 novel The Green Ray:
“All eyes were again turned towards the west. The sun seemed to sink with greater rapidity as it approached the sea; it threw a long trail of dazzling light over the trembling surface of the water; its disk soon changed from a shade of old gold, to fiery red, and, through their half-closed eyes, seemed to glitter with all the varying shades of a kaleidoscope. Faint, waving lines streaked the quivering trail of light cast on the surface of the water, like a spangled mass of glittering gems.
Not the faintest sign of cloud, haze, or mist was visible along the whole of the horizon, which was as clearly defined as a black line traced on white paper.
Motionless, and with intense excitement, they watched the fiery globe as it sank nearer and nearer the horizon, and, for an instant, hung suspended over the abyss. Then, through the refraction of the rays, its disk seemed to change till it looked like an Etruscan vase, with bulging sides, standing on the water. There was no longer any doubt as to the appearance of the phenomenon. Nothing could now interfere with this glorious sunset! Nothing could prevent its last ray from being seen!
The sun was just half way below the horizon, and its powerful rays were shot across the sky like golden arrows; in the distance the cliffs of Mull and the summit of Ben More were bathed in brilliant, purple light.
At last only a faint rim of gold skimmed the surface of the sea.
‘The Green Ray! The Green Ray!’ cried in one breath the brothers, Dame Bess, and Partridge, whose eyes for one second had revelled in the incomparable tint of liquid jade.”