This image features a deep field view of the Cassiopeia constellation immersed in the glow of ionized hydrogen gas, where the ...

Narrator: Fireworks have been around for millennia. They flood the sky with brilliant bursts of scarlet, emerald, and ivory. But never blue. Pyrotechnicians have tried to produce blue fireworks ...

But think of dark clouds behind which the sun is hidden. As a cloud comes out from behind the dark clouds into a bright blue sky, it is edged with a silvery lining. Thus we are moving from ...