Which of the following statements is not true planetary orbits? a. A planet’s mass does not affect how fast it orbits its star.
b. A planet travels faster in its orbit when it closer to the star it is orbiting.
c. The square of the period of a planet's orbit is inversely proportional to the radius of its orbit cubed.
d. Planets have elliptical orbits with the star they orbit as one of the ellipses’ foci.