In 20th century, astronomers opened their minds to gazillions of galaxies
Telescopes in U.S. West revealed vastly larger, expanding universe

In 1923, Edwin Hubble found variable stars in the Andromeda nebula enabling him to gauge its distance. It turned out to be far from the Milky Way, demonstrating that it and many other nebulae were actually galaxies in their own right.
JPL-Caltech/NASA
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