Request for Info: Is it possible to plot only a portion of an ellipse?

[espinielli]

I am wondering whether it is possible to plot only part of an ellipse in geom_ellipse(), say from angle alpha to angle beta.
For example I would like to plot only the front part of an ellipse (think of the circle as the Earth, and the black ellipse as the Equator and the red ellipse ad a satellite) from the following code/plot:

ggplot() +
  geom_circle(aes(x0 = 0, y0 = 0, r = 1), fill ="white", alpha = 1) +
  geom_ellipse(aes(x0 = 0, y0 = 0, a = 1.0, b = 0.1, angle = 0), colour = "black") +
  geom_ellipse(aes(x0 = 0, y0 = 0, a = 1.05, b = 0.1, angle = pi / 6), colour = "red") +
  coord_fixed() +
  theme_void()

Any helps much appreciated.