Question

For an astronaut in a spaceship, the sky appears black due to:
A. Absence of atmosphere in his surrounding
B. Light from the sky is absorbed by the medium surrounding him
C. The fact at the height, sky radiations are only in the infra-red and ultraviolet region
D. None of these

Answer 1

We see the objects surrounding us due to reflection and refraction of photons incident on the object falls on the retina of our eye. You can imagine why the light does not get reflected in the space to answer this question.

Complete step by step answer:
We see the object surrounding us is due to the fact that the photons from the object reflect towards the retina of the eye. We know that the color of the object is due to different scattering wavelengths.
To answer this question we should answer why the sky looks blue? The molecules in our atmosphere scatter light from the sun in all directions. Therefore, we see the bright sky due to incident photons to our retina from all directions. In space, there is no atmosphere to refract or reflect the sunlight. Therefore, no photons would reach the retina of our eye. So, we can say the astronaut in a spaceship sees a dark sky due to the absence of atmosphere surrounding him.
If we stand on the surface of the Moon we will see a dark sky because there is no atmosphere on the moon to refract the sunlight.
There is no atmosphere in space. Therefore, we can say the light will not get absorbed by the atmosphere. Therefore, the option (B) is incorrect.
The sky radiations have a wide range of wavelengths including visible light, ultraviolet and infrared light.
So, the correct answer is “Option A”.

Note:
Note that if the astronaut sees the dark sky does not mean there is absence of sunlight. The astronaut will see his spaceship from outside the spaceship as the spaceship will reflect off the photons incident on it.