Have you seen an ancient map of the world produced in the B.C. era? For example, look up the 194 B.C. map attributed to Eratosthenes of Cyrene. Some better known regions (such as the Mediterranean) are poor but identifiable representations, while farther regions (such as Africa and Asia) are wildly out of proportion, and still other regions (such as the Americas) remain absent.
Presently the map of our own galaxy is at a similar stage. The new Gaia mission of the European Space Agency (ESA) will improve this, enabling a better understanding of the developing and changing structure of our galaxy, and the past and future motion of our Solar System through our galaxy.
View original post 791 more words