The difference between how light behaves on Earth and how it travels in the emptiness of space, explains the beautiful blue skies and the vast darkness of space. Why is the sky blue in colour?

ROCHESTER, N.Y. – You know that beautiful, clear blue sky over Rochester? It’s always a welcome sight—when it happens. But have you ever noticed the thin white streaks that sometimes ...

new video loaded: A Curious Blue Swirl of Light Captivates Sky Watchers in Europe The Met Office, Britain’s weather service, said the light was most likely caused by a SpaceX rocket launch.