In 1920, astronomers Harlow Shapley and Heber Curtis held a Great Debate. Shapley argued that the spiral nebulae were small and in the Milky Way, while Curtis took a more radical position that they ...

Hubble’s work pushed the field of astronomy forward, starting with his paper demonstrating that some objects exist outside ...

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 ...

A century ago, Edwin Hubble first established that this so-called 'spiral nebula' was actually very far outside our own Milky Way galaxy -- at a distance of approximately 2.5 million light-years ...

A century ago, Edwin Hubble first established that this so-called "spiral nebula" was actually very far outside our own Milky Way galaxy —at a distance of approximately 2.5 million light-years ...

Observations show Andromeda has a more active star formation history than the Milky Way, potentially due to a past galactic collision. NASA recently released images of the Andromeda galaxy ...

of Washington) The Andromeda galaxy ... a proxy for spiral galaxies in the universe at large, astronomers would know much less about the structure and evolution of our own Milky Way," NASA said.

In 1952, astronomers began the first major radio survey of the Milky Way. Astronomers theorized that the galaxy had a spiral structure, and finally, they detected the spiral arms, revealing the Milky ...