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Unit 2: The Universe
About this unit
The Universe is all the matter, energy, and space that exists, and the observable universe is the part that we can see. While there are still great mysteries about how it all began and evolved, we are living in an age of rapid cosmic discovery. Astrophysicists use observations from telescopes on the ground and in space, spacecraft return data from the outer reaches of our solar system, models based on the mathematical laws of physics reveal the structure and history of the universe and our place in it. These simulations, videos, and essays, cover the formation, evolution, and properties of stars, planets, galaxies, and the universe.