Answer:
planet's orbital eccentricity and semi-major axis
Step-by-step explanation:
The eccentricity and the semi - major axis controls the size and shape of the orbit of the planet . The value for the semi major axis is equal to the half of largest diameter of the elliptical orbit .
The eccentricity controls the shape of elliptical orbit . It is the ratio of the center to the focus ( sun ) length and the semi - major axis length .