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 ...

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 ...

The two keys to Edwin Hubble's breakthrough discovery were forged by others in the 1910s. The first key, the period-luminosity scale discovered by Henrietta Leavitt, allowed astronomers to ...

A hundred years ago, astronomer Edwin Hubble dramatically expanded the size of the known universe. At a meeting of the American Astronomical Society in January 1925, a paper read by one of his ...

American astronomer Edwin Hubble was the one who made the discovery, and it put him onto greater things. In 1919, Hubble began working at Mount Wilson and used the 100-inch Hooker telescope ...

The largest photomosaic of the Andromeda galaxy, assembled from over a decade of observations by the NASA/ESA Hubble Space Telescope, has unveiled a stunning portrait of our neighboring galaxy ...