Most textbooks of physics present the terrestrial orbit by a drawing which shows an ellipse of substantial eccentricity. This suggests a remarkable variation of the distance between Sun and Earth during the year up to a value of about 3:1 and more. Imagine the dramatic variation in size of the radiating area of the Sun seen by the terrestrial inhabitants with all the terrible consequences for temperature. All this is not true. There is no obvious change in size of the solar disc.