They turned their telescopes towards other nearby galaxies.他们把望远镜转向附近其他星系。Quasars are the highly energetic cores of distant galaxies.类星体是遥远星系的极为活跃的核心体.We still don't know how many galaxies there are in the universe....
By measuring the motion of the galaxies in a cluster, astronomers can infer the cluster's mass.通过测量星系在一个星系团内的运动,天文学家们可以推定这个星系团的质量。They turned their telescopes towards other nearby galaxies...他们把望远镜转向附近其他星系。Space fli...