Hubble revealed a universe of galaxies that existed beyond ours — but he couldn't have done it without a little help.

In the 1920s, astronomers thought that the Milky Way was the entire universe. Hubble's discovery revealed a much bigger ...

Edwin Powell Hubble is renowned for determining that there are other galaxies in the Universe beyond the Milky Way, and for observing that the universe is expanding at a constant rate. Hubble was ...

Edwin Hubble's discovery of a Cepheid variable star in the Andromeda galaxy in 1923 revealed that the universe extends far beyond the Milky Way, fundamentally altering our understanding of the cosmos.