Question

Why earth appears blue from the space?

• A. About 71% of the earths surface is covered with water which gives blue colour to earth.
• B. Earth is covered with blue air.
• C. Earth is covered with blue coloured mountains and rocks.
• D. All of the above.

Answer 1

Answer: (A)

About 71% of the earths surface is covered with water which gives blue colour to earth.

• The earth is predominantly (71 % of the earth's surface) covered with water. Water absorbs the white light in the radiation (sunlight). The sunlight through appears white it is actually a combination of lights of several different colors (Violet, indigo, blue, green, yellow, orange and red).
• When sunlight reaches the water; the water absorbs, lights of all colors in the white light and reflects only blue light. Thus, the earth from space appears blue. If the water absorbs all colors and reflects only yellow, then it would appear yellow.