A friend of yours who has not taken an astronomy class looks at your textbook and really likes the picture of the Pleiades, a cluster of stars surrounded by a bluish reflection nebula. She wants to know what causes that beautiful blue glow. To explain it to her, you want to compare the process that causes the blue glow to something that is in your friend's everyday experience. Which of the following terrestrial phenomena is the result of the same type of process that makes a reflection nebula in space?

Question

Quizplus · Accepted Answer

The blue color of the Earth's sky is caused by the scattering of sunlight off of the atmosphere's molecules, specifically oxygen and nitrogen. This process is similar to the scattering of light off of small dust particles in a reflection nebula, which creates the bluish glow. Therefore, the blue color of the Earth's sky is the terrestrial phenomenon that is most similar to the process that causes the blue glow in a reflection nebula.

A Friend of Yours Who Has Not Taken an Astronomy