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  2. Geocentric model - Wikipedia

    en.wikipedia.org/wiki/Geocentric_model

    Pages from 1550 Annotazione on Sacrobosco's De sphaera mundi, showing the Ptolemaic system. In the Ptolemaic system, each planet is moved by a system of two spheres: one called its deferent; the other, its epicycle. The deferent is a circle whose center point, called the eccentric and marked in the diagram with an X, is distant from the Earth.

  3. Historical models of the Solar System - Wikipedia

    en.wikipedia.org/wiki/Historical_models_of_the...

    In 1588, Tycho Brahe publishes his own Tychonic system, a blend between the Ptolemy's classical geocentric model and Copernicus' heliocentric model, in which the Sun and the Moon revolve around the Earth, in the center of universe, and all other planets revolve around the Sun. [70] It was an attempt to conciliate his religious beliefs with ...

  4. Astronomical coordinate systems - Wikipedia

    en.wikipedia.org/.../Astronomical_coordinate_systems

    The geocentric ecliptic system was the principal coordinate system for ancient astronomy and is still useful for computing the apparent motions of the Sun, Moon, and planets. [3] It was used to define the twelve astrological signs of the zodiac , for instance.

  5. Barycentric and geocentric celestial reference systems

    en.wikipedia.org/wiki/Barycentric_and_geocentric...

    The geocentric system is simpler, being smaller and involving few massive objects: that coordinate system defines its center as the center of mass of the Earth itself. The barycentric system can be loosely thought of as being centered on the Sun, but the Solar System is more complicated. Even the much smaller planets exert gravitational force ...

  6. Planetary coordinate system - Wikipedia

    en.wikipedia.org/wiki/Planetary_coordinate_system

    Chart of lunar maria with lines of longitude and latitude. The prime meridian is the centre of the near side of the Moon.. A planetary coordinate system (also referred to as planetographic, planetodetic, or planetocentric) [1] [2] is a generalization of the geographic, geodetic, and the geocentric coordinate systems for planets other than Earth.

  7. Jet Propulsion Laboratory Development Ephemeris - Wikipedia

    en.wikipedia.org/wiki/Jet_Propulsion_Laboratory...

    The models consist of numeric representations of positions, velocities and accelerations of major Solar System bodies, tabulated at equally spaced intervals of time, covering a specified span of years. [1] Barycentric rectangular coordinates of the Sun, eight major planets and Pluto, and geocentric coordinates of the Moon are tabulated.

  8. List of orbits - Wikipedia

    en.wikipedia.org/wiki/List_of_orbits

    In the Solar System, all planets, comets, and asteroids are in such orbits, as are many artificial satellites and pieces of space debris. Moons by contrast are not in a heliocentric orbit but rather orbit their parent object. Geocentric orbit: An orbit around the planet Earth, such as that of the Moon or of artificial satellites.

  9. Deferent and epicycle - Wikipedia

    en.wikipedia.org/wiki/Deferent_and_epicycle

    The orbits of planets in this system are similar to epitrochoids, but are not exactly epitrochoids because the angle of the epicycle is not a linear function of the angle of the deferent. In the Hipparchian system the epicycle rotated and revolved along the deferent with uniform motion.