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 spirals and ellipticals in our backyard showed us, a century ago, that the Milky Way wasn’t alone.
Even earlier astronomers still had copious bright galaxies they could observe with their telescopes.
By measuring the speeds and distances of these galaxies, we discovered the expanding Universe.
Without them, we might never have understood our cosmic origins: the hot Big Bang.
Unfortunately, not every observer in the Universe gets so lucky.
Most galaxies clump together in groups, clusters, or along filaments, but some reside in underdense regions.
The Universe’s large-scale structure contains great cosmic voids as well as overdense clumps.
In these extremely underdense regions, however, galaxies still occasionally form.
This is the galaxy MCG+01–02–015, which may be the loneliest galaxy in the Universe.
In all directions, we find no other galaxies within 100 million light-years of it.
If we had grown up there, our telescopes would not have observed other galaxies until the 1960s.
Perhaps we are truly fortunate: our serendipitous position in the Universe allowed us to understand it.
Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words. Talk less; smile more.Ethan Siegel is the author of Beyond the Galaxy and Treknology. You can pre-order his third book, currently in development: the Encyclopaedia Cosmologica.