Book 20, Question 44
Why Does the Sky Look Darker From a Mountaintop?
The sky looks darker from a mountaintop because there is less air above you! The sky is blue because air scatters sunlight in all directions. Less air means less scattered light.
More fun facts
- All colors of sunlight are scattered by air molecules, but violet and blue are scattered the most.
- This scattering is called Rayleigh scattering, after Lord John Rayleigh, who first described it in the 1870s.
- Higher up, there are fewer air molecules to scatter light, so the sky looks a deeper, darker blue.
- If you kept going upward, the sky would slowly turn black as the scattering fades away.
- Space looks black because it has very few molecules to scatter light.
Sources: National Weather Service
Questions kids ask
Would the sky be black if you went high enough?
Yes. Far above the air, there is almost nothing to scatter sunlight, so the sky turns black.