The modern heliocentric model of planetary motion states that the planets travel around..

Kepler's Laws of Planetary Motion. While Copernicus rightly observed that the planets revolve around the Sun, it was Kepler who correctly defined their orbits. At the age of 27, Kepler became the assistant of a wealthy astronomer, Tycho Brahe, who asked him to define the orbit of Mars. Hope this helps!

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i have to report this, it doesn't relate to biology