Carl asked Dad for help crafting the message while the two of them were in San Juan, Puerto Rico, for a meeting of the American Astronomical Society. Dad recalls that, in the lobby of the San Gerónimo Hilton, he and Carl quickly came up with ideas about what to include: line drawings depicting humans, a rendering of the spacecraft -- and then, "in the next moment, we hit on the idea of a galactic map that would pinpoint the location of the Earth in space."

Dad designed that map, and in 1972 it flew into space aboard Pioneer 10. The next year Pioneer 11 launched, ultimately carrying the map past Saturn and now on to the stars. Then in 1977 both Voyager spacecraft left Earth carrying Dad's guide to finding our planet, which is etched onto the cover of the "golden record." The way Dad designed the map means that it points back to Earth both in space and in time, making it a galactic positioning system (a different kind of GPS) in four dimensions.