What causes reflection nebulae to appear blue while emission nebulae appear pink?
A) Reflection nebulae contain less hydrogen than emission nebulae.
B) Reflection nebulae are hotter than emission nebulae.
C) Reflection nebulae are less ionized than emission nebulae.
D) Long wavelengths of light are preferentially scattered by small dust grains.

Question

Quizplus · Accepted Answer

Reflection nebulae appear blue because they scatter shorter wavelengths of light, like blue, more effectively than longer wavelengths. Emission nebulae appear pink due to the ionization of hydrogen gas, which emits light primarily in the red part of the spectrum (H-alpha line).

What Causes Reflection Nebulae to Appear Blue While Emission Nebulae