Question

The sky appears dark to passengers flying at very high altitude

Answer 1

The sky appears dark instead of blue to passengers 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 passengers and the sky appears black to them.

Answer 2

Answer:

The sky appears dark instead of blue to passengers because there is no atmosphere in the outer space that can scatter the sunlight.