In science, astronomers must analyze many observations and separate out those that provide evidence in support a specific theory. To reinforce the credibility of a theory, astronomers must look for multiple, independent pieces of evidence. Consider the following example: Astronomers believe that every bright galaxy harbors a supermassive black hole at its center. Sort the following observations according to whether they support or do not support this theory. Fast motions of closely orbiting material in galactic nuclei, Powerful jets of high-speed material, Exceptionally bright galactic nuclei. Stellar black holes in interacting binary systems, Globular clusters in the outer galactic haloes, Spiral arms in the outer disks of galaxies.