A miniature sky. Also called an orrery. It represents this stellar system, as I represent you.
The makers understood that their suns—not their own world, nor even their giant Jovian—lay at the center of things. A fine humility. Perhaps this discovery is why the orrery was preserved as a museum.
You might scan the gems within to learn more. The orrery could warn of dangerous cosmic events. And it will be impossible to return home without fixing our position in the galaxy.