If the sky is black in space, what colour would it be if lit up?
The blue of our sky is due to the scattering of the blue wavelengths of sunlight by our atmosphere. Since there is no atmosphere in space (the estimated density in space outside of our solar system is only about a few thousands particles per cubic meter (the density of Earth’s atmosphere is millions of times greater). So even if there was an extremely bright light source in space, there would not be enough matter in space to “light up space” as it would on a planet or other object with an atmosphere of some kind. It would be very bright when you looked at the light source, but shadows would be completely black and the sky would still be black.
