Solar System model
Solar 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.
If the smaller planets are to be easily visible to the naked eye, large outdoor spaces are generally necessary, as is some means for highlighting objects that might otherwise not be noticed from a distance. The Boston Museum of Science placed models of the planets in major public buildings, all on similar stands with interpretive material. For example, the model of Jupiter, shown, is located in the cavernous South Station waiting area. The properly scaled, basket-ball sized model is 1.3 miles from the model Sun which is located at the museum, graphically illustrating the immense empty space in the Solar System.
The objects in such large models do not move. Traditional orreries often did move and some used clockworks to make the relative speeds of objects accurate. These can be thought of as being correctly scaled in time instead of distance.
Scale models in various locations
Many towns and institutions have built outdoor scale models of the Solar System. Here is a table comparing these models.| Name | Location | Scale | Sun dia. | Earth dia. | Sun–Earth | Sun–Pluto | Description |
| Actual statistics | 1:1 | 1.392 Gm | 12.76 Mm | 149.6 Gm | 5.914 Tm | ||
| Sweden Solar System | 1:20,000,000 | 71 m | 65 cm | 7,600 m | 300 km | permanent; country-wide | |
 Coonabarabran, New South Wales | 1:38,000,000 | 37 m | 34 cm | 4,100 m | 205 km | permanent; drivable | |
 University of Maine at Presque Isle, Maine | 1:93,000,000 | 15 m | 13.7 cm | 1,600 m | 64 km | permanent; drivable | |
| Peoria, Illinois | 1:125,000,000 | 11 m | 10.0 cm | 1,200 m | 47 km | permanent; drivable | |
 Vienna | 1:163,764,706 | 8.5 m | 7.78 cm | 913 m | 36 km | under construction since 2018. Physical + Augmented Reality | |
| Planet Lofoten |  Lofoten | 1:200,000,000 | 7 m | ? | ? | 30 km | under construction |
| Madison - Mt. Horeb, Wisconsin | 1:200,000,000 | 7 m | 6.6 cm | 777 m | 38.3 km | permanent; fully accessible by foot and bike paths | |
 Sunspot, New Mexico | 1:250,000,000 | 5.6 m | 5.1 cm | 1.5 m | 23,6 km | permanent, drivable | |
| If the Earth were a Ping-Pong ball |  Westminster, London | 1:318,905,000 | 4.36 m | 40 mm | ? | ? | In construction; Walk & Drive Centered around Deans Yard, Westminster |
| Anchorage, Alaska | 1:350,000,000 | ? | ? | 16.6 km | permanent; drivable | ||
| Moab, Utah | 1:400,000,000 | 3.6 m | ? | ? | 15.3 km | permanent; Walk and Drive | |
| Boston, Massachusetts | 1:400,000,000 | 3.5 m | 3.2 cm | 380 m | 15.3 km | permanent; drivable | |
 Estremoz | 1:414,000,000 | 3.4 m | 3.1 cm | 361 m | 14.3 km | permanent; drivable; bikeable | |
| Somerset Space Walk | Bridgwater and Taunton Canal, Somerset | 1:530,000,000 | 2.5 m | ? cm | ? m | 11 km | permanent; bikeable |
| York, England | 1:575,872,239 | 2.4 m | 2.2 cm | 260 m | 10.3 km | permanent; bikeable | |
| Coleman, Midland County. Michigan, USA | 1:608,000,000 | 2.3 m | 2.1 cm | 324 m | 9.8 km | permanent; bike trail Sun and Pls. Spheres | |
| Nine Views |  Zagreb | 1:680,000,000 | 2.0 m | 1.9 cm | 225 m | 8.7 km | permanent; bikeable |
 Fort St. John, British Columbia | 1:682,353,000 | 2.0 m | 1.9 cm | 219 m | 8.6 km | under construction | |
| New Milford, Connecticut | 1:761,155,000 | 1.8 m | 1.7 cm | 195 m | 7.1 km | permanent; bikeable | |
| Glen Burnie to Severna Park, Maryland. Northern terminus at ; southern terminus at. | 1:781,000,000 | ? | ? | 191.5 m | 7.56 km | Walkable, bikeable. Part of the permanent Baltimore & Annapolis Trail. | |
| Área de Paisagem Protegida do Corno de Bico, Paredes de Coura | 1:831,000,000 | 1.675 m | 1.533 cm | 180 m | 5.42 km | permanent; walkable; bikeable | |
 Helsinki | 1:1,000,000,000 | 1.4 m | 1.2 cm | 149.6 m | 6.1 km | permanent; bikeable | |
 Hagen | 1:1,000,000,000 | 1.4 m | 1.3 cm | 150 m | 5.9 km | permanent; bikeable | |
| Kriftel | 1:1,000,000,000 | 1.4 m | 1.3 cm | 150 m | 5.9 km | permanent; bikeable | |
 Zurich | 1:1,000,000,000 | 1.4 m | 1.3 cm | 150 m | 5.9 km | permanent; bikeable | |
| Ehrenfriedersdorf, Drebach and Heidelbachtal | 1:1,000,000,000 | 1.4 m | 1.3 cm | 150 m | 5.9 km | permanent; bikeable | |
 Hradec Králové | 1:1,000,000,000 | 1.4 m | 1.3 cm | 150 m | 5.9 km | permanent; bikeable | |
| Prague | 1:1,000,000,000 | 1.4 m | 1.3 cm | 150 m | 13 km | permanent; bike & walk; all objects above 1000km; | |
| Melbourne | 1:1,000,000,000 | 1.4 m | 1.3 cm | 150 m | 5.9 km | permanent; bikeable | |
| Eugene, Oregon | 1:1,000,000,000 | 1.4 m | 1.2 cm | 150 m | 5.9 km | permanent; bikeable | |
| Sandnes | 1:1,000,000,000 | 1.4 m | 1.2 cm | 150 m | 5.9 km | permanent; walkable, bikeable | |
| Munich | 1:1,290,000,000 | 1.1 m | 1.0 cm | 116 m | 4.6 km | permanent; walkable | |
| La Malbaie, Quebec | 1:1,500,000,000 | 0.9 m | 0.8 cm | 100 m | 3 km | permanent; walkable | |
| :sv:Göteborgs Naturhistoriska museum#Rymdpromenaden|Rymdpromenaden |  Gothenburg | 1:2,000,000,000 | 0.7 m | 0.6 cm | 75 m | 3 km | permanent; walkable |
| Akaa Solar System Scale Model | Akaa, Finland | 1:3,000,000,000 | 0.46 m | 0.4 cm | 49.9 m | 1,958 m | permanent; walkable, Proxima Centauri in Yulara, Australia |
| Elmhurst, Illinois | 1:3,044,620,000 | 0.5 m | 0.4 cm | 49.1 m | 1,929 m | permanent; walk & drive | |
| Wooster, Ohio | 1:5,000,000,000 | 0.3 m | 0.3 cm | 30 m | 1.2 km | permanent; walkable | |
| Göttingen | 1:2,000,000,000 | 0.70 m | 0.65 cm | 75 m | 3.2 km | permanent; walkable/bikeable | |
| Gainesville, Georgia | 1:2,000,000,000 | 0.7 m | 0.6 cm | 75 m | 2.9 km | permanent; walkable | |
| Norwich, Vermont | 1:2,200,000,000 | 0.6 m | 0.6 cm | 68 m | 2.7 km | permanent; walkable | |
| Ride to Pluto: Boise's Solar System | Boise Greenbelt, Boise, Idaho | 1:2,200,000,000 | 0.5 m | n/a | 2.4 km | permanent; walkable & bikeable; | |
| Longview, Washington | 1:? | 0.6 m | 0.6 cm | ? m | 2.7 km | permanent; walkable | |
 Westerbork | 1:3,700,000,000 | ? | ? | ? | 2.5 km | permanent; walkable | |
| Gainesville, Florida | 1:4,000,000,000 | 0.3 m | 0.3 cm | 37.4 m | 1.5 km | permanent; walkable | |
| Otford, England | 1:4,595,700,000 | 0.3 m | 0.3 cm | 32 m | 0.9 km | permanent; walkable | |
| The Sagan Planet Walk | Ithaca, New York | 1:5,000,000,000 | 0.3 m | 0.3 cm | 30 m | 1.2 km | permanent; walkable |
| University City, Missouri | 1:5,000,000,000 | 0.3 m | 0.2 cm | 30 m | 0.87 km | permanent; walkable | |
| Cleveland, Ohio | 1:5,280,000,000 | 0.3 m | 0.2 cm | 28.4 m | 1.1 km | permanent; walkable | |
| Solar System Walk An Exploration of Scale | Carlsbad, California | 1:5,280,000,000 | 28 m | 1,119 m | Located near Lake Calavera ] | ||
 Natal | 1:7,000,000,000 | 20 cm | 1.8 mm | 22 m | 875 m | permanent; walkable/bikeable | |
| National Mall, Washington, D.C. Space Center Houston, Texas Corpus Christi, Texas | 1:10,000,000,000 | 0.1 m | 0.1 cm | 15 m | 0.6 km | ||
| New Jersey State Botanical Garden | Ringwood, New Jersey | 1:10,000,000,000 | 0.2 m | 2.0 cm | 23.8 m | 927 m | walkable |
| Fiske Planetarium, Boulder, Colorado | 1:10,000,000,000 | 0.1 m | 0.1 cm | 15 m | 0.6 km | permanent; walkable | |
| Anstruther, Scotland | 1:10,000,000,000 | 0.1 m | 0.1 cm | 15 m | 0.6 km | permanent; walkable | |
 La Couyère, Brittany | 1:10,000,000,000 | 1 m | 0.1 cm | - | 0.45 km | permanent; walkable | |
| Toronto, Ontario and Eureka, Nunavut | 1:10,000,000,000 | 0.14 m | 0.13 cm | 15 m | 0.591 km | permanent; walkable/bikeable | |
| | 1:1,000,000,000 | 1.4 m | 1.3 cm | 150 m | 6 km | permanent; walkable/bikeable |
| Name | Location | Scale | Sun dia. | Earth dia. | Sun-Earth | Sun-Pluto | Description |
| Scotland | 1:8,200,000 | 170 m | 156 cm | 18,300 m | 551 km | ||
| England | 1:15,000,000 | - | - | - | - | under construction; country-wide. Partially dual scale | |
| The Hague, Netherlands | 1:696,000,000 | 2.0 m | 1.8 cm | 215 m | 6.5 km | ||
| Illinois, Chicago | 1:73,660,000 | 19 m | 17.3 cm | 2,050 m | 61 km | proposed | |
| Saint-Luc, Switzerland | 1:1,000,000,000 | 1.4 m | 1.3 cm | 150 m | 5.9 km | uses two different scales for distance and size | |
| Madison, Wisconsin | 1:4,000,000,000 | 0.3 m | 0.3 cm | 37 m | 1.5 km | ||
| Perth, Western Australia | 1:5,000,000,000 | 0.3 m | 0.3 cm | 30 m | 1.2 km | permanent; walkable | |
| 1:6,336,000,000 | 0.2 m | 0.2 cm | 25 m | 1 km | |||
| Saint-Louis-du-Ha! Ha!, Quebec | 1:10,000,000,000 | 0.1 m | 0.1 cm | 15 m | 0.6 km | ||
| Lafayette Walk | Detroit, Michigan | 1:6,336,000,000 | 23 cm | 0.2 cm | 25 m | 983 m | A Walking Demonstration of imaginable distances. "It's nowhere near Graham's Number." |
| Chicago, Illinois | 1:2,195,000,000 | 457 m | 11.4 m | ||||
| PDF for printing | 1:11,945,400,000 | 11.6 cm | 0.1 cm | 12.5 m | 492 m | PDFs, A4 and 8½″×11″, to be printed, affixed to cards which are affixed to sticks; then to be held by children standing in a school yard. Includes major moons and asteroids. |
Several sets of geocaching .
A model based on a classroom globe
If the Earth were reduced to the size of a typical classroom globe, 41 cm in diameter, the Moon would be a 10 cm baseball floating 12 metres away. The Sun would be 14 stories tall floating away. While a complete model to this scale has never been built, a Solar System built centered in Washington DC, London, or Sydney, to that scale would look like this:| Body | Diameter | object comparison | Semi-major axis | scale model location | scale model location | scale model location |
| Sun | 44.6 m ' | 14 story tall sphere, Spaceship Earth | zero | White House, Washington DC | Buckingham Palace | Sydney Opera House |
| Mercury | 15 cm ' | large grapefruit | 1.9 km ' | National Air and Space Museum | Covent Garden | Elizabeth Bay |
| Venus | 38 cm ' | beach ball | 3.5 km ' | John F. Kennedy Eternal Flame, Arlington National Cemetery | Regent's Park | Sydney Football Stadium |
| Earth | 41 cm ' | classroom globe | 4.8 km ' | Ronald Reagan Washington National Airport | Tower of London | Rozelle Hospital |
| Moon | 10 cm ' | baseball | 12 m ' from Earth | - | - | |
| Mars | 23 cm ' | dodgeball | 7.2 km ' | Rock Creek Park Golf Course | King's College London | Bondi Beach |
| Ceres | 3 cm ' | golf ball | 13.3 km ' | - | - | |
| Jupiter | 4.55 m ' | Commercial van | 24.9 km ' | George Mason University, Fairfax, Virginia | Heathrow Airport | Scotland Island |
| Saturn | 3.81 m ' | Roundabout | 45.5 km ' | Marine Corps Base Quantico, Triangle, Virginia | Luton | Copacabana |
| Uranus | 1.63 m ' | average 8th grade boy | 92.2 km ' | Aberdeen Proving Ground, Aberdeen, Maryland | Waterlooville | Bombo |
| Neptune | 1.55 m ' | average 6th grade boy | 144.4 km ' | Newark, Delaware | Leicester | Nelson Bay |
| Pluto | 7 cm ' | baseball | 190 km ' | Wildwood, New Jersey | Hereford | Bulahdelah |
| Eris | 8 cm ' | baseball | 325 km ' | Brooklyn, New York | Blackpool | Port Macquarie |
| α Centauri A | 49.5 m ' | Spaceship Earth | 1,323,500 km | over 3 times the distance to the Moon | over 3 times the distance to the Moon | over 3 times the distance to the Moon |
If the scale of the above model is increased to 1:310 000 000, i.e. all distances and sizes reduced by a factor of 10, then the Earth and Venus can be modeled by ping pong balls, the Moon and smaller planets by various size marbles or lumps of modeling clay, the gas giants by balloons or larger playing balls, and a circle the diameter of the Sun can be drawn on the floor of most classrooms. The scale distance to Alpha Centauri would be 1/3 of the way to the Moon.
Some planetaria and related museums often use a scale model of the Solar System featuring a planetarium dome representing the Sun. Examples of this can be seen in planetaria like the Adler Planetarium, the Hayden Planetarium at the American Museum of Natural History, the Clark Planetarium, the Griffith Observatory, the Louisiana Arts and Science Museum, the Adventure Science Center, etc.
A commonly-portrayed scale model of the Solar System would use fruits of varying sizes to represent the planets: The Sun would be represented by an adult human, Mercury would be represented by a pea, Venus by a cherry or a grape, Earth by a strawberry or an apricot, the Moon by a peppercorn, Mars by a blueberry, Jupiter by a watermelon or a medium-sized pumpkin, Saturn by a grapefruit or a large melon like a cantaloupe or a honeydew, Uranus by an apple or an orange, and Neptune by a lime or a plum.