Why is the earth blue (from space)?
Seventy percent of the Earth's surface is covered by oceans. From space, the ocean is what appears blue.
So why do the oceans appear blue? There are many reasons, but the biggest reason is sunlight.
Sunlight is a mixture of the seven colors of rainbow, and only the blue of the seven colors penetrates deep into the ocean, making it appear blue. The other colors are absorbed by the seawater in the process and disappear.
In addition, when the sun's rays hit the air and dust in the air, only the blue color is reflected, which also causes the entire earth to appear somewhat blue.
In other words, the combination of water and sunlight makes the earth appear blue. The earth is sometimes referred to as the "water planet," and it is because it is surrounded by water that it appears blue.
