This stunning image features a deep field view of the Cassiopeia constellation where the two small planetary nebulas can be ...

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 ...