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 had placed bronze models of the planets in major public buildings, all on similar stands with interpretive labels.[1] For example, the model of Jupiter was located in the cavernous South Station waiting area. The properly-scaled, basket-ball-sized model is 1.3 miles (2.14 km) 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 display the relative speeds of objects accurately. These can be thought of as being correctly scaled in time, instead of distance.
Permanent true scale models
Many towns and institutions have built outdoor scale models of the Solar System. Here is a table comparing these models with the actual system.
permanent; walkable; Includes: Proxima Centauri in Los Angeles, USA; Barnard’s Star in Port Stanley, Falkland Islands; Sirius in Sydney, Australia; and Ross 154 in Christchurch, New Zealand
The scale of the planets is the same as the scale between them, and the planets are represented by everyday objects; the Earth is a peppercorn, Jupiter is a walnut, and Neptune is a coffee bean.
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.
In Ireland, this instantly recognisable roadside spherical sculpture is well known, and is used as the model for the Sun. The website[55] maps out the planetary orbits and shows everyday objects to scale the planets (e.g. a golf ball for Mars)
Interplanetary spaceflight or interplanetary travel is the crewed or uncrewed travel between stars and planets, usually within a single planetary system. In practice, spaceflights of this type are confined to travel between the planets of the Solar System. Uncrewed space probes have flown to all the observed planets in the Solar System as well as to dwarf planets Pluto and Ceres, and several asteroids. Orbiters and landers return more information than fly-by missions. Crewed flights have landed on the Moon and have been planned, from time to time, for Mars, Venus and Mercury. While many scientists appreciate the knowledge value that uncrewed flights provide, the value of crewed missions is more controversial. Science fiction writers propose a number of benefits, including the mining of asteroids, access to solar power, and room for colonization in the event of an Earth catastrophe.
The Sun is the star at the center of the Solar System. It is a massive, hot ball of plasma, inflated and heated by energy produced by nuclear fusion reactions at its core. Part of this energy is emitted from its surface as light, ultraviolet, and infrared radiation, providing most of the energy for life on Earth. The Sun has been an object of veneration in many cultures. It has been a central subject for astronomical research since ancient times.
Solar sails are a method of spacecraft propulsion using radiation pressure exerted by sunlight on large surfaces. A number of spaceflight missions to test solar propulsion and navigation have been proposed since the 1980s. The first spacecraft to make use of the technology was IKAROS, launched in 2010.
The zodiacal light is a faint glow of diffuse sunlight scattered by interplanetary dust. Brighter around the Sun, it appears in a particularly dark night sky to extend from the Sun's direction in a roughly triangular shape along the zodiac, and appears with less intensity and visibility along the whole ecliptic as the zodiacal band. Zodiacal light spans the entire sky and contributes to the natural light of a clear and moonless night sky. A related phenomenon is gegenschein, sunlight backscattered from the interplanetary dust, appearing directly opposite to the Sun as a faint but slightly brighter oval glow.
An 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 1713, 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.
An apsis is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides is the line connecting the two extreme values.
Space weather is a branch of space physics and aeronomy, or heliophysics, concerned with the varying conditions within the Solar System and its heliosphere. This includes the effects of the solar wind, especially on the Earth's magnetosphere, ionosphere, thermosphere, and exosphere. Though physically distinct, space weather is analogous to the terrestrial weather of Earth's atmosphere. The term "space weather" was first used in the 1950s and popularized in the 1990s. Later, it prompted research into "space climate", the large-scale and long-term patterns of space weather.
The solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun's activity measured in terms of variations in the number of observed sunspots on the Sun's surface. Over the period of a solar cycle, levels of solar radiation and ejection of solar material, the number and size of sunspots, solar flares, and coronal loops all exhibit a synchronized fluctuation from a period of minimum activity to a period of a maximum activity back to a period of minimum activity.
The interplanetary medium (IPM) or interplanetary space consists of the mass and energy which fills the Solar System, and through which all the larger Solar System bodies, such as planets, dwarf planets, asteroids, and comets, move. The IPM stops at the heliopause, outside of which the interstellar medium begins. Before 1950, interplanetary space was widely considered to either be an empty vacuum, or consisting of "aether".
The interplanetary dust cloud, or zodiacal cloud, consists of cosmic dust that pervades the space between planets within planetary systems, such as the Solar System. This system of particles has been studied for many years in order to understand its nature, origin, and relationship to larger bodies. There are several methods to obtain space dust measurement.
Nine Views is an ambiental installation in Zagreb, Croatia which, together with the sculpture Prizemljeno Sunce, comprises a scale model of the Solar System.
Solar physics is the branch of astrophysics that specializes in the study of the Sun. It intersects with many disciplines of pure physics, astrophysics, and computer science, including fluid dynamics, plasma physics including magnetohydrodynamics, seismology, particle physics, atomic physics, nuclear physics, stellar evolution, space physics, spectroscopy, radiative transfer, applied optics, signal processing, computer vision, computational physics, stellar physics and solar astronomy.
The Sweden Solar System is the world's largest permanent scale model of the Solar System. The Sun is represented by the Avicii Arena in Stockholm, the second-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, professor at the Royal Institute of Technology in Stockholm, and Gösta Gahm, professor at the Stockholm University. The model represents the Solar System on the scale of 1:20 000 000, i.e. one metre represents 20,000 km.
The Max Planck Institute for Solar System Research is a research institute in astronomy and astrophysics located in Göttingen, Germany, where it relocated in February 2014 from the nearby village of Lindau. The exploration of the Solar System is the central theme for research done at this institute.
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 Mercury, Venus, Mars, Jupiter, Saturn, Uranus, and Neptune, their satellites, as well as smaller bodies including comets, asteroids, and dust.
The 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.
The 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.
The following outline is provided as an overview of and topical guide to the Solar System:
Venus has an orbit with a semi-major axis of 0.723 au, and an eccentricity of 0.007. The low eccentricity and comparatively small size of its orbit give Venus the least range in distance between perihelion and aphelion of the planets: 1.46 million km. The planet orbits the Sun once every 225 days and travels 4.54 au in doing so, giving an average orbital speed of 35 km/s (78,000 mph).
Historical models of the Solar System began during prehistoric periods and are updated to this day. The models of the Solar System throughout history were first represented in the early form of cave markings and drawings, calendars and astronomical symbols. Then books and written records became the main source of information that expressed the way the people of the time thought of the Solar System.
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