The Expanding Universe investigation uses authentic data from supernovae and galaxies along with interactive analysis and visualization tools to create and explore Hubble plots, which are then used by students through a sequence of tasks and questions to discover evidence about the origin and expansion rate of the Universe. We will begin with an overview of the warm-up activity, followed by brief instructions of how to access and navigate the investigation. Participants will then collaboratively explore sections of the investigation in breakout rooms. We will conclude with an overview of the accompanying support materials and other website and online resources for educators.