To map out how clusters of galaxies are distributed in the universe, astronomers needed to know where each cluster was in the sky AND
A) how many galaxies were in each cluster
B) how blue or red the galaxies in each cluster were
C) how far away from us each cluster was
D) whether any of the galaxies in each cluster acted like quasars
E) whether any gravitational lensing could be seen in each cluster

Question

Quizplus · Accepted Answer

To map out the distribution of clusters of galaxies in the universe, astronomers have to know where each cluster is in the sky, but also need to determine how far away from us each cluster is. This information is necessary to obtain a three-dimensional map of the distribution of clusters in the universe. The size, color, or the presence of quasars and gravitational lensing are not essential parameters for this map.

To Map Out How Clusters of Galaxies Are Distributed in the Universe