The galaxy shown at the center of the image here, MCG+01–02–015, is a barred spiral galaxy located inside a great cosmic void. It is so isolated that if humanity were located in this galaxy instead of our own and developed astronomy at the same rate, we wouldn’t have detected the first galaxy beyond our own until the 1960s. (ESA/HUBBLE & NASA AND N. GORIN (STSCI); ACKNOWLEDGEMENT: JUDY SCHMIDT)

Scientists Discover The Loneliest, Most Isolated Galaxy In The Entire Universe

Imagine how different our understanding of the Universe would be if we saw nothing beyond the Milky Way.

Our corner of the Universe was gifted with a plethora of bright, nearby galaxies to light our way through the cosmos.

The Large (top right) and Small (lower left) Magellanic Clouds are visible in the southern skies, and helped guide Magellan on his famous voyage some 500 years ago. In reality, the LMC is located some 160–165,000 light-years away, with the SMC slightly farther away at 198,000 light-years distant. Along with Triangulum and Andromeda, these four galaxies beyond our own are visible to the naked human eye. (ESO/S. BRUNIER)

The spirals and ellipticals in our backyard showed us, a century ago, that the Milky Way wasn’t alone.

This sketch from the mid-1840s is the first ever one to reveal the spiral structure of any nebula in the night sky. Now known to be a spiral galaxy, Messier 51, the Whirlpool Galaxy, is one of the most well-studied galaxies beyond our Milky Way. (WILLIAM PARSONS, 3RD EARL OF ROSSE (LORD ROSSE))

Even earlier astronomers still had copious bright galaxies they could observe with their telescopes.

A selection of approximately 2% of the galaxies in the Virgo cluster. There are approximately 1,000 large galaxies in the Virgo cluster, a large fraction of which were discovered way back in the 18th century. The Virgo cluster is located some 50–60 million light-years away from our Milky Way, and is the largest concentration of galaxies in the extremely nearby Universe. (JOHN BOWLES OF FLICKR)

By measuring the speeds and distances of these galaxies, we discovered the expanding Universe.