Water is clear. The sky is blue. So why are clouds white? And if regular clouds are white, why are rain clouds gray? On sunny days, at picnics, we relax ...

Sometimes, under direct sunlight, clouds will appear gray or dark gray against a blue sky or larger backdrop of white clouds. There are usually two reasons for this effect.

This is why the sky looks blue. A similar thing happens with objects all over the world. Grass looks green, for example, because grass will absorb all but green light.

Cloud computing and blue-sky thinking: An atmospheric scientist illuminates the science of clouds in Earth’s sky and beyond. Studying the physics and microphysics of cloud formation and behavior in ...

Earth's polar skies have shined with eerie blue-white glowing clouds slowly twisting and undulating in the twilight sky every summer since the late 19th century. These mystifying clouds are ...

Blue-white clouds that eerily glow in the twilight sky are called noctilucent clouds, or NLCs. ... Backhouse noticed ghostly filaments glowing blue against the black sky.

Night sky photographer Ruslan Merzlyakov captured bright blue-white noctilucent clouds dancing over Nykøbing Mors in Denmark just before dawn on July 1.