Geocentric model that both Venus and Mercury went around the Sun rather than the Earth, but this is no longer accepted. Martianus Capella definitely put Mercury and Venus in orbit around the Sun. Aristarchus of Samos was the most radical. He wrote a work, which has not survived, on heliocentrism, saying that the Sun was at the center of the universe, while the Earth and other planets revolved around it. His theory was not popular, and he had one named follower, Seleucus of Seleucia. In 1543, the geocentric system met its first serious challenge with the publication of Copernicus' "De revolutionibus orbium
National Register of Historic Places listings in Central Baltimore city park system are included in the federally designated Baltimore National Heritage Area. National Register of Historic Places listings in Central Baltimore This is a list of National Register of Historic Places properties and districts in downtown Baltimore, Maryland, United States. Many other properties are located in other parts of the city; for these, see National Register of Historic Places listings in Baltimore, Maryland. The locations of the National Register properties and districts listed below (at least for all showing latitude and longitude coordinates below) may be seen in a map by clicking on "Map of all coordinates". Much of