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 and one or two sentences make a hypothesis about the movement of the Galaxy and explain at least one way to test that
Hypothesis: The newly discovered Galaxy is moving away from the Milky Way due to the expansion of the universe.
One way to test this is by measuring the redshift of the Galaxy's light. If the light coming from the Galaxy shows a redshift, it would indicate that the Galaxy is moving away from the Milky Way. The larger the redshift, the faster the Galaxy is moving away.