<P> Most planetary orbits are nearly circular , and careful observation and calculation are required in order to establish that they are not perfectly circular . Calculations of the orbit of Mars , whose published values are somewhat suspect , indicated an elliptical orbit . From this , Johannes Kepler inferred that other bodies in the Solar System , including those farther away from the Sun , also have elliptical orbits . </P>
<P> Most planetary orbits are nearly circular , and careful observation and calculation are required in order to establish that they are not perfectly circular . Calculations of the orbit of Mars , whose published values are somewhat suspect , indicated an elliptical orbit . From this , Johannes Kepler inferred that other bodies in the Solar System , including those farther away from the Sun , also have elliptical orbits . </P>
who proposed elliptical orbit of the planets around sun
who proposed elliptical orbit of the planets around sun
Johannes Kepler
Johannes Kepler