Which sequence of formation is most likely to be correct, oldest to youngest?
A) emission nebulae, planetary nebulae, dark nebulae
B) halo, spiral arms, globular clusters
C) planetary nebulae, Population I stars, population II stars
D) Population I stars, population II stars, population III stars
E) globular clusters, open clusters, OB associations

Question

Quizplus · Accepted Answer

Globular clusters are among the oldest structures in the universe, containing some of the most ancient stars. Open clusters are younger, containing relatively young stars. OB associations are groups of very young, massive stars that have recently formed. This sequence correctly represents the transition from older to younger astronomical objects.

Which Sequence of Formation Is Most Likely to Be Correct