Why is the Sky Blue?
Light from the Sun looks white, but it’s actually a mix of many colors. When sunlight hits Earth's atmosphere, it bumps into tiny particles and air molecules.
Light travels in waves, and each color has a different wave size. Some colors travel in big waves, others in smaller waves. The air molecules scatter light in all directions.
Blue light scatters more than the other colors because it travels in shorter, smaller waves. The scattered blue light comes from everywhere in the sky, so when you look up, you see a blue sky all around you.
There are a couple of special cases to notice:
- Sunrise and sunset: The Sun is low on the horizon. Its light has to travel through more air, so more colors scatter out, and you often see reds and oranges.
- Clear days: The sky looks very blue because there aren’t many particles to disturb the light.
So, the sky is blue mainly because air molecules scatter blue light from the Sun in every direction.