Scientists have incredibly advanced tools to look at the stars today, but in the era before light pollution, star-gazing was much easier and simpler for the average person -- just step outside at night. Pretty early on, and in a variety of cultures, people realised that they could chart the stars and their movements for navigation. The Greek constellations, which were tied to their myths, illustrate how this information moved through time. But humanity's early star maps are much more than ancient artifacts -- they became part of our history and culture, and continue to inform modern science to a surprising degree.