An accurately scaled (5x10⁹:1) model of the solar system found in Ithaca, New York. The sun is located in the Ithaca Commons, and the various planets are located at appropriately scaled distances. While Mercury, Venus, Earth and Mars are all within 50m of the sun, Pluto is located way out at the Sciencenter, 1.18 km away. The walk was named in memory of Carl Sagan, an astronomer and science educator who taught at Cornell University.