Unofre B. Pili, Harold P. Bulanon, Remalyn V. Fajardo
The semi-major axes and orbital periods of selected comets and asteroids were collected from online databases. Subsequently, the square of the period was plotted as a function of the cube of the semi-major axis for both comets and asteroids, with the generated plots showing agreement with Kepler’s third law of planetary motion. The same law was empirically derived by plotting the orbital period and semi-major axis directly against each other, again using the comet and asteroid data. Finally, Newton’s version of Kepler’s third law and the values of the optimized fitting parameters in the linear model enabled the determination of the solar mass. The accuracy of the obtained Sun’s mass is accurate to less than 1.00%. This article also proposes an inquiry-based approach to teaching Kepler’s third law of planetary motion. © 2026 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.
Department of Physics, University of San Carlos, Cebu City, 6000, Philippines
