Just to get things into perspective, scientists also estimate that the Milky Way is one of between 100 and 200 billion galaxies in the Universe. Take care not to break your brain when you think about that. Our galaxy’s name originates from the Greek galaxías kýklos, which translates as “milky circle.” And for most of human history, that was about the best description we had of our galaxy.
We have the Italian Galileo Galilei to thank for our first scientific breakthrough with regard to the Milky Way. In 1610, looking through a telescope, he was the first to see that the soupy cloud in the night sky was in fact an array of individual stars. In his 1941 A Short History of Science to the Nineteenth Century, Charles Singer called Galileo the “father of observational astronomy.” It’s a well-deserved accolade.
But, after Galileo’s insight, the general level of ignorance about the nature of the Milky Way was to remain high for centuries. In fact, right up until the 1920s, it was believed that the Milky Way comprised all the stars in the universe. Indeed, it wasn’t until the astronomer Edwin Hubble came along and pointed out that the Milky Way was but one of many galaxies that this misconception was nailed in 1923.