The Royal Institution Christmas Lectures
The Earth as a Planet
1977 • E1 Dec 26, 1977 40m
In his first Christmas Lecture, American astronomer and cosmologist Carl Sagan explores planet Earth and the place, scale and geometry of the “pale blue dot” in the Solar System.
Sagan provides a unique insight into the history of our knowledge of the third planet from the Sun, formed 4.5 billion years ago.
Using images and models of the planets in our Solar System, Sagan reveals how the heliocentric model of our universe, in which the Earth and planets revolve around the Sun, came to replace the earlier Aristotelian idea that our planet was at the centre and everything orbited around it.
Sagan provides a unique insight into the history of our knowledge of the third planet from the Sun, formed 4.5 billion years ago.
Using images and models of the planets in our Solar System, Sagan reveals how the heliocentric model of our universe, in which the Earth and planets revolve around the Sun, came to replace the earlier Aristotelian idea that our planet was at the centre and everything orbited around it.
