The sun's _______ keeps planets in our solar system in orbit around the sun. Comets are examples of bodies that complete parabolic or _______ orbits. Kepler's laws describe how objects move through space; _______ laws describe why objects move in this way. Respond to the following based on your reading. Describe the differences between a geocentric model and heliocentric model. What model is the current Sun-Earth-Moon System based on?
