Question

Explain why the sky appears dark instead of blue to an astronaut

Answer 1

The sky which we see (blue) is due to the scattering of smaller wavelengths of the visible spectrum of light.

Since, the astronauts are above the atmosphere, there is no medium for light to scatter. And also the light emitted by the sun is lost in deep space, leaving no object or medium to reflect.

Hence, nothing can be seen in deep space but darkness.

Answer 2

Explanation:

The sky appears dark instead of blue to an astronaut because there is no atmosphere in the outer space that can scatter the sunlight. As the sunlight is not scattered, no scattered light reach the eyes of the astronauts and the sky appears black to them.