Recently, we took a look at GPS and the space science that makes it work. This time, we're going back to an era when navigators had nothing but their equipment and the stars to tell them where they were, even on the open ocean.Celestial navigation combined the sextant, almanac and chronometer to make a reliable navigation system that just needed one other thing, the sun and the stars... And some handy astronomical knowledge!  Follow Cosmic Coffee Time on Twitter for some special content twitter.com/CosmicCoffTimeYou can request a topic for the show! Or even just say hi!We'd love to hear from you.Email us!cosmiccoffeetime@gmail.com