The author’s first essay about the universe was actually about the presence of dwarf galaxies, called “The Galaxy and the Seven Dwarfs.” The title points to something still more fascinating than the fact that there are mini galaxies around—there are far more of them than galaxies proper.

So why are we just now discovering them? Part of the reason is that they are significantly smaller clusters, with far fewer stars. This makes the dwarf galaxies appear dimmer and easy to miss. Scientists speculate that because they have as few as one million stars instead of hundreds of billions like other galaxies, the chances of their discovery are about 100 thousand times slimmer.