The darkness of space is not caused by shadows from planets and stars. The darkness of space primarily arises from the absence of light sources in vast regions of the universe. Here are a few points to consider:
Distance between celestial objects: In space, objects such as planets and stars are typically separated by vast distances. The light emitted by a star or a planet illuminates its immediate surroundings, but as the distance increases, the light diminishes. Eventually, in the vast expanses of space between celestial bodies, the amount of light becomes extremely low, resulting in darkness.
Lack of scattering medium: On Earth, the atmosphere scatters sunlight, resulting in a blue sky during the day. However, in space, there is no significant scattering medium like an atmosphere. Consequently, when you look away from a light source in space, there is no scattering of light to illuminate the surrounding space, leading to darkness.
Interstellar dust and gas: While space is mostly empty, there are regions containing interstellar dust and gas clouds. These clouds can obscure light and create areas of relative darkness. However, these regions are localized and do not account for the darkness of space as a whole.
It's important to note that when we see images of space taken by telescopes or astronauts, the darkness is often portrayed as black to represent the absence of significant light sources. However, these images may capture faint background light from distant stars and galaxies, which are too dim to be individually perceived by the human eye. Nonetheless, the darkness between celestial bodies in space is primarily due to the absence of significant light sources rather than shadows cast by individual objects.