WSolar System models, especially mechanical models, called orreries, that illustrate the relative positions and motions of the planets and moons in the Solar System have been built for centuries. While they often showed relative sizes, these models were usually not built to scale. The enormous ratio of interplanetary distances to planetary diameters makes constructing a scale model of the Solar System a challenging task. As one example of the difficulty, the distance between the Earth and the Sun is almost 12,000 times the diameter of the Earth.
WAkaa Solar System Scale Model is located at the center of the city of Akaa, Finland. The Sun is located at the school campus of Toijalan Yhteiskoulu –school in Toijala district. The scale of the model is 1 : 3 000 000 000, meaning that each centimetre in the scale model represents 30 000 km in real life. The Sun is 464 mm in diameter and the Earth is 4 mm in diameter and located 49.86 meters away from the Sun. Neptune is 1500 meters away from the Sun, for example. Akaa Solar System Scale Model was built in 2017 by amateur astronomer Kari-Pekka Arola.
WKystagerparken is a park located in Hvidovre, Denmark, it borders Kalveboderne, the waters between Zealand and Amager. The nearest station is Åmarken.
WAn orrery is a mechanical model of the Solar System that illustrates or predicts the relative positions and motions of the planets and moons, usually according to the heliocentric model. It may also represent the relative sizes of these bodies; however, since accurate scaling is often not practical due to the actual large ratio differences, a subdued approximation may be used instead. Though the Greeks had working planetaria, the first orrery that was a planetarium of the modern era was produced in 1704, and one was presented to Charles Boyle, 4th Earl of Orrery – hence the name. They are typically driven by a clockwork mechanism with a globe representing the Sun at the centre, and with a planet at the end of each of the arms.
WThe Pajamäki Solar System Scale Model is a scale model of the Solar system built in Helsinki and partly in Espoo, Finland in 1992. Its scale is 1:1 000 000 000, i.e. one to one billion, so that 1 millimeter in the model corresponds to 1 000 kilometers in the actual solar system. The coordinates given for the model are those for the Sun in Patterinmäki.
WThe Sciencenter's Sagan Planet Walk is a walkable scale model of the Solar System, located in Ithaca, New York. The model scales the entire Solar System—both planet size and distances between them—down to one five billionth of its actual size. The exhibition was originally created in 1997 in memory of Ithaca resident and Cornell Professor Carl Sagan.
WThe Somerset Space Walk is a sculpture trail model of the Solar System, located in Somerset, England. The model uses the towpath of the 22-kilometre (14-mile) Bridgwater and Taunton Canal to display a model of the Sun and its planets in their proportionally correct sizes and distances apart. Unusually for a Solar System model, there are two sets of planets, so that the diameter of the orbits is represented.
WThe Sweden Solar System is the world's largest permanent scale model of the Solar System. The Sun is represented by the Ericsson Globe in Stockholm, the largest hemispherical building in the world. The inner planets can also be found in Stockholm but the outer planets are situated northward in other cities along the Baltic Sea. The system was started by Nils Brenning and Gösta Gahm and is on the scale of 1:20 million.
WA tellurion, is a clock, typically of French or Swiss origin, surmounted by a mechanism that depicts how day, night, and the seasons are caused by the rotation and orientation of Earth on its axis and its orbit around the Sun. The clock normally also displays the age of the Moon and the four-year (perpetual) calendar.