John Pimple’s night is cut short by a terrible noise. He looks out of the window and sees the culprit’s silhouette against the rising sun. What was it that disturbed John’s slumber?
You’re probably used to blue skies in the day and red sunsets in the evening, but on Mars it would be the other way round. The Martian sky is red during the day and turns blue when the sun sets or rises. The effect is due to a phenomenon called Raleigh scattering, and it is at work on the red planet as well as on Earth.