All of the stars that you can see with your unaided eye at night belong to a vast swirl of stars known as the Milky Way Galaxy, seen here in a video I made a few years ago. Here is another very nice time-lapse video of the Milky Way as our turning Earth causes the Home Galaxy to glide across our night sky. We see our home galaxy as a cloud-like arch across dark skies. The Sun is one of a few hundred billion stars that orbit the center of our galaxy. We have not always known that we live in a spiral galaxy. For the last three or four centuries, we have been discovering more and more details of our place in the universe. Galileo was the first to realize that band of light across the night sky consisted of thousands of stars visible only through a telescope. In the late eighteenth century, William Herschel had a fairly simple, and incorrect, view of our place in the universe. Although his effort to map our home galaxy was the first of its kind, Herschel did not not know of the importance of interstellar dust and its effects on the brightness of stars. It was about eighty years ago when Harlow Shapley and his contemporaries first understood the true nature of the galaxy in which we live. Although the new ideas certainly were not accepted without debate. But we do agree on its basic structure. Today, we can make much more accurate maps of our home galaxy., though they don’t always agree If you are confused about the various depictions of the spiral arms of our home galaxy, consider this map of North and South America from more than four hundred sixty years ago.