The Tusi couple, developed by Nasir al-Din al-Tusi, was initially used to address the latitudinal motion of inferior planets and served as a substitute for the equant in astronomical models. While it is related to plotting ellipses, it does not equate to the discovery of the laws of planetary motion as formulated by Johannes Kepler. The Tusi couple represents a geometric solution rather than a comprehensive understanding of planetary orbits, which Kepler later defined as elliptical. Kepler's second and third laws, which describe the areas swept by planets and the relationship between orbital periods and distances, are considered more significant advancements in the understanding of planetary motion than the Tusi couple's contributions. Thus, while Tusi's work laid important groundwork, it did not fully encompass the laws of planetary motion as established by Kepler.
