Why does a reflection nebula primarily display a blue appearance due to light interaction?
Smaller particles scatter blue light more efficiently than red light.
A reflection nebula occurs when a cloud of interstellar dust primarily scatters the light originating from nearby stars rather than emitting its own light through excitation. The key to its blue appearance lies in the physics of light scattering off the fine cosmic dust grains. These particles, often comparable in size to molecules or small micrometer-sized objects, scatter shorter wavelengths of light, such as blue light, much more efficiently than longer wavelengths, like red light. This physical phenomenon is analogous to Rayleigh scattering, which is responsible for making Earth's daytime sky appear blue, as the dust preferentially redirects blue photons towards the observer.
