The diagram shows the Earth's orbit in comparison with a circle centered on the Sun. The foci of the orbital ellipse and the positions of aphelion and perihelion are indicated. The count of ecliptical longitude starts at the First Point of Aries (the direction of the vernal equinox).
<a href="//commons.wikimedia.org/wiki/User:Sch" title="User:Sch">Sch</a>
CC BY-SA 3.0
Drawn by myself. The orbit has been plotted using orbital positions calculated with the planetary theory VSOP87A for the year 2000.