<P> Discovery and exploration of the Solar System is observation, visitation, and increase in knowledge and understanding of Earth's "cosmic neighborhood". This includes the Sun, Earth and the Moon, the major planets including Mercury, Venus, Mars, Jupiter, Saturn, Uranus, and Neptune, their satellites, as well as smaller bodies including comets, asteroids, and dust . </P> <P> The Solar System--our Sun's system of planets, moons, and smaller debris--is humankind's cosmic backyard . Small by factors of millions compared to interstellar distances, the spaces between the planets are daunting, but technologically surmountable </P> <P> For many thousands of years, astronomers maintained a geocentric world view and did not recognize the existence of a Solar System . Most believed Earth was stationary at the center of the Universe and categorically different from the divine or ethereal objects that moved through the sky . Although the Greek philosopher Aristarchus of Samos had speculated on a heliocentric reordering of the cosmos, Nicolaus Copernicus in the 16th century developed a mathematically predictive heliocentric system . His 17th - century successors, Galileo Galilei, Johannes Kepler, and Isaac Newton, developed a modern understanding of physics that led to the gradual acceptance of the idea that Earth moves around the Sun and that the planets are governed by the same physical laws that govern Earth . In more recent times, this led to the investigation of geological phenomena such as mountains and craters and seasonal meteorological phenomena such as clouds, dust storms, and ice caps on the other planets . </P> <Table> <Tr> <Td> </Td> <Td> This section needs expansion . You can help by adding to it . (December 2010) </Td> </Tr> </Table>

Who discovered that the planets orbit the sun