When Copernicus reordered our solar system, epicycles were not longer required to demonstrate retrograde motion of planets. Additionally, the relationships that each planet's motion held with the Sun no longer needed to be included in their planetary models. The models demonstrate the limited elongation of Inferior Planets, the retrograde motion of the Sun, and the connection between Superior Planets' retrograde motion of the Sun as consequences of the Earth's motion around the Sun.
The Planet and the Earth each travel in circular orbits at uniform speed around the Sun. The observed elongation between the Planet and the Sun is shown. [br]
The Animate checkbox will animate the motion. The Speed slider adjusts the speed of the Earth around its orbit. When Speed = 1, a tropical year passes every 10s of real time. The Sidereal Period slider adjusts the relative period of the planet around its orbit in units of tropical years. [br][br]The Orbit Size slider defines the size of the planet's orbit in astronomical units, (AU). [br][br]When the Animate checkbox is not checked, a Planet Position slider will appear allowing the user to move the planet around its orbit. [br][br]The two buttons named Mercury and Venus will set the values of the orbital parameters to their respective values.
The Planet and the Earth each travel in circular orbits at uniform speed around the Sun. The observed elongation between the Planet and the Sun is shown. [br]
The Animate checkbox will animate the motion. The Speed slider adjusts the speed of the Planet around its orbit. When Speed = 1, a sidereal period passes every 10s of real time. A tropical year, the period of Earth's orbit will pass by faster. The Sidereal Period slider adjusts the speed of the Earth's orbit so that the sidereal period of the planet will relative to a tropical year. [br][br]The Orbit Size slider defines the size of the planet's orbit in astronomical units, (AU). [br][br]When the Animate checkbox is not checked, an Earth Position slider will appear allowing the user to move the Earth around its orbit. [br][br]The three buttons named Mars, Jupiter, and Saturn will set the values of the orbital parameters to their respective values.