Orbital motions of astronomical bodies and their Centre of Mass from different reference frames: a conceptual step between the Geocentric and Heliocentric models

TL;DR

This paper explores how understanding the change of reference frames and the concept of the centre of mass can improve students' comprehension of astronomical motions, bridging the gap between geocentric and heliocentric models.

Contribution

It introduces a conceptual approach using simple methods and examples to help students grasp complex motions and the importance of reference frames in astronomy.

Findings

Students can better understand planetary motions through simple 'do it yourself' methods.

The approach facilitates conceptual change in understanding reference frames.

Enhanced comprehension of the transition from geocentric to heliocentric models.

Abstract

The motion of astronomical bodies and the centre of mass of the system is not always well perceived by students. One of the struggles is the conceptual change of reference frame, which is the same that held back the acceptance of the Heliocentric model over the Geocentric one. To address the question, the notion of centre of mass, motion equations (and their numerical solution for a system of multiple bodies), and change of referential is introduced. The discussion is done based on conceptual and real world examples, using the solar system. Consequently, through the use of simple "do it yourself" methods and basic equations, students can debate complex motions, and have a wider and potentially effective understanding of physics.