Most open clusters in our Milky Way are about how old?

Question

Quizplus · Accepted Answer

Most open clusters in our Milky Way are less than a billion years old. Although there is some variation in the ages of stars within a single open cluster, they tend to form around the same time period, giving them a similar age range. Most open clusters in our Milky Way are less than a billion years old. While there is some variation in age among stars within a single open cluster, the majority of open clusters are relatively young. Choice A is incorrect because most open clusters are not less than a million years old. Choice B is partly true in that there is some variation in age among stars within a single open cluster, but it is not the best choice because it does not address the age range of most open clusters as a whole. Choice D is incorrect because most open clusters are not around ten billion years old. Choice E is incorrect because twenty billion years is older than the age of the universe, so there cannot be open clusters that old.

Most Open Clusters in Our Milky Way Are About How