jan 1, 1924 - Edwin Hubble

Description:

He found Cepheid variables contained in nebulas previously discovered,(including in the Andromeda Nebula) and through analysis found that the stars were too far away to be in our galaxy, and were actually separate other galaxies.

This changed everything, as many thought-to-be nebulas were now separate galaxies, and we only thought that the Milky Way was the only galaxy in the universe. He would go on to create the tuning-fork classification system based on the discovery, which some scientists use to this day.

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