1) The eccentricity of Earth's orbit is currently 0.0169. If the semi-major axis of the orbit is a = 149,598,261 km, calculate how big the semi-minor axis b is. How stretched out is the orbit, i.e. how big is a - b?
Over the next 100,000 years, the orbital eccentricity will vary, becoming as much as 0.06. At that time, if a remains the same, how big will a - b be?