A space object (dubbed 2003 UB313), larger and more distant than Pluto, was discovered in 2003. In its elliptical orbit with the sun at one focus, it is 3.5 billion miles from the sun at the closest, and 9.0 billion miles at the farthest. What is the eccentricity of its orbit? See Exercise 46.

Data from Exercises 46

The eccentricity e of an ellipse is defined as e = c/a. A cam in the shape of an ellipse can be described by the equation x² + 9y² = 81. Find the eccentricity of this elliptical cam.