Question

An astronaut in outer space will observe the sky as________________.
A.) White
B.) Black
C.) Blue
D.) Red

Answer 1

Hint: No particles exist in the sky so light does not scatter in the sky and without scattering of light, the sky would appear black.

Complete step by step answer:

Scattering of light – when a parallel beam of light passes through a gas, a part of it appears in directions other than the incident direction. This phenomenon is called scattering of light. The basic concept behind Scattering of light is absorption of light by molecules followed by its re-radiation in different directions. The red light scattered the least and violet is scattered the most.

The sky appears blue on Earth due to scattering of sunlight from the atmosphere. When we look at the sky, it is scattered light that enters the eyes. It appears blue because the color blue is present in sunlight in a larger proportion so blue color is scattered most. Hence the appearance of light is blue. But in outer space there is no scattering of light. There are no particles in space so there is no scattered light, and hence no light will reach the astronaut and astronaut in outer space will observe sky as Black.

Note: The sky appears light blue on a humid day before it rains and the sky appears deep blue on a clear day because the air molecules, water particles, dust etc also scatter light. And in rains, the light is also scattered by water molecules of rain so appears light blue.