Multiple choice

The sky appears blue when there is an atmosphere. What would be the colour of the sky when there is no atmosphere?

  1. White

  2. Black

  3. Red

  4. Blue

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The blue color of the sky is caused by Rayleigh scattering of sunlight by the atmosphere. Without an atmosphere, there is no scattering, so the sky appears black.