On the golden record that accompanies the Voyager spacecraft, there is a map showing the location of Earth.  It’s not a road map that you might pull out when navigating a city, but a 3D map showing the location of a star, the Sun, in a populous galaxy.  But just how would this map work? And more importantly, what are the map markers? If you notice the lines at the bottom left of the golden record image, they all intersect at a common center point.  This is the Sun, and the lines extend out showing relative distances to the nearest...