You can never know too much, so here are some more places to learn about the universe and the history of our understanding of it:

What does it mean when they say the universe is expanding? The idea that the universe is expanding can be a very challenging concept. Learn more about exactly what that means in one of The Library of Congress’s “Everyday Mysteries”.

What tools did ancient astronomers use? The video briefly touched on some of the tools of astronomy. NASA’s “Ask an Astrophysicist” has more about how those tools have been developed and refined over time.

Cosmic Questions Exhibit: You can browse this online exhibition from Smithsonian Astrophysical Observatory on cosmic questions and find a range of supporting classroom activities in this educator guide.

Views of the Universe: This online exhibition from The Library of Congress includes an extensive set of primary sources documenting the history of our understanding of the heavens from around the world.

The Explore The Universe online exhibition from the Smithsonian National Air and Space Museum shows how our ideas about the Universe evolved as we developed new astronomical instruments. It includes several interactives that illustrate these ideas.