An astronomer discovers a new galaxy using a telescope. The astronomer wants to investigate how the galaxy is moving relative to the Milky Way galaxy.
In one or two sentences, make a hypothesis about the movement of the galaxy and explain at least one way to test the hypothesis.
Hypothesis: The new galaxy is moving away from the Milky Way galaxy due to cosmic expansion.
Testing the hypothesis: The astronomer can analyze the galaxy's redshift to determine if its spectral lines are shifted towards longer wavelengths, indicating a recession velocity and confirming the hypothesis.