The Sky at Night — Episode 10: Autumn Equinox

You are watching the episode Autumn Equinox Patrick Moore , with the aid of a sundial at his Selsey home, explains why equinoxes occur, and shows how the seasons of the year vary, due to the tilt of the Earth's axis. Other planets in the solar system have different axial tilts and therefore different seasons; PATRICK MOORE compares them with those of our own world.