Photo/Reuters/Lee Smith

Kast was searching for clear skies in Finnish Lapland to capture the beauty of a polar night when he encountered these polar stratospheric clouds.

50 years apart

Do them today.

A natural limestone monolith located at the village of Katskhi in the western Georgian region of Imereti.

by @SylviaDuckworth on Instagram.

"Ever stared down the gaping eye of a category 4 hurricane? It's chilling, even from space," says European Space Agency astronaut Alexander Gerst, who is currently living and working aboard the International Space Station as a member of the Expedition 56 crew.

On a journey to Norway, "the lady in green" unexpectedly appeared for Roemmelt, making the whole sky burn with green, blue and pink colours.

An image of a single positively-charged strontium atom, held near motionless by electric fields, has won the overall prize in a national science photography competition, organised by the Engineering and Physical Sciences Research Council (EPSRC).

What creates the colors in Jupiter's clouds? No one is sure. The thick atmosphere of Jupiter is mostly hydrogen and helium, elements which are colorless at the low temperatures of the Jovian cloud tops. Which trace elements provide the colors remains a topic of research, although small amounts of ammonium hydrosulfide are one leading candidate. What is clear from the featured color-enhanced image -- and many similar images -- is that lighter clouds are typically higher up than darker ones. Pictured, light clouds swirl around reddish regions toward the lower right, while they appear to cover over some darker domains on the upper right.