From the August 2009 issue

How a scientist discovered we lived in one galaxy of many

Until 84 years ago astronomers thought the Milky Way Galaxy was the entire universe. Then they found that fuzzy objects in the sky were galaxies themselves.
By | Published: August 21, 2009 | Last updated on May 18, 2023
Andromeda Galaxy
Also known as M31, the Andromeda Galaxy is the furthest-away object that can be viewed with the naked eye.
T. A. Rector/B. A. Wolpa/NOAO/AURA/NSF

Edwin Hubble (1889-1953) joined the Mount Wilson Observatory staff in 1919, a few years after earning his Ph.D. from the University of Chicago. His research goal was to study galactic nebulae (the nebulous objects scattered throughout the Milky Way). He would perform that research on the newly completed 100-inch Hooker telescope, the largest in the world at that time.