Question

A reflection nebula is made visible by

a. emission lines from hydrogen, which itself has been ionized by UV light from embedded stars.

b. blue light, preferentially scattered by tiny dust grains.

c. light from embedded stars reflected over a wide range of wavelengths toward Earth, by crystals of water, methane, and ammonia ices.

d. thermal energy emitted as a continuous spectrum by very hot gas, much like that emitted by a hot body on Earth.

Answer 1

A reflection nebula appears visible because of blue light, preferentially scattered by tiny dust grains.

Step-by-step explanation:

A reflection nebula appears visible because of blue light, preferentially scattered by tiny dust grains. These dust grains scatter the light from nearby bright stars, causing the reflection nebula to shine and be visible.

This is similar to how fog around a street lamp becomes visible because of scattered light.