The orbits of planets are ellipses. Their equations are entered in the Input field, selected in such way that they have in common the Sun in one of their focuses. One orbit belongs to a comet. The Sun is represented by the yellow circle for which is not difficult to provide its equation. Every planet is represented by a small circle which will move along its respective orbit. Experience the visualization of the system by selecting in the slider the option Animation On.

Find out which equation belongs to which planet (which orbit). [br]Can you construct a simple system consisted of the sun and a planet moving along an elliptical orbit?[br]Find out what tools are used to construct the system and how.