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
Long Term Ecological Research Network Long Term Ecological Research Network The Long Term Ecological Research Network (LTER) consists of a group of over 1800 scientists and students studying ecological processes over extended temporal and spatial scales. Twenty-six LTER sites cover a diverse set of ecosystems. It is part of the International Long Term Ecological Research Network (ILTER). There are 28 sites within the LTER Network across the United States, Puerto Rico, and Antarctica, each conducting research on different ecosystems. LTER sites are both physical places and communities of researchers. Some of the physical places are remote or protected from development, others are deliberately located in