tools Edit Export E-Sign sun at one foci. 98 3 Td Law A C. In equal intervals of time, a planet's orbit sweeps out equal areas. Explain how Tycho Brahe helped Kepler make important discoveries in astronomy: 2. Which labeled location in Fig. la can the Sun be located at? B 3. Assume that the diagram in Figure la is the elliptical orbit of a planet E around the Sun. A) Label the two focal points (foci) with an X B) Which labeled location corresponds to the Perihelion? C) Which labeled location corresponds to the Aphelion? Figure la. Elliptical Orbit The eccentricity of an ellipse is defined as: eccenticity = distance between the foci length of the major axis where the length of the major axis is the longest distance you can draw within the ellipse; the full distance between location C and F in Figure la for example