Stargazers in parts of Europe were stunned by an unusual sight on Monday evening: a large, glowing blue spiral in the sky.

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 relative darkness into bright light and the meaning of the idiom ...

This satellite picture shows the Cirrus Radiatus clouds and the blue arrows show direction of jet stream A fan of pink and yellow streaks decorate the blue sky over a frosty field in Coulsdon ...