Altitudes, landscapes and climates change dramatically as you move across the globe, but one factor remains nearly ubiquitous. All of Earth's diversity is blanketed under a blue sky. But why is the sky blue? It's not a reflection of Earth's oceans. The real explanation requires a bit of particle physics.
We see blue above us because of how light from the sun interacts with Earth's atmosphere. The visible light spectrum contains a variety of colors, ranging from red light to violet. When all of the colors are mixed, the light appears white, Marc Chenard, a meteorologist at the National Weather Service, told Live Science. But once the white light traveling from the sun reaches Earth, some of the colors begin to interact with molecules and small particles in the atmosphere, he said.
