Episode 1 "The Shores of the Cosmic Ocean"

A few comments where the info might be a little old.
The Local Group of galaxies is thought to include about 40 not 20. The Milky Way is thought to be a barred spiral not just a spiral. Pluto is mentioned as a planet not as a "dwarf" planet.
It's always amazing how advanced many of the astronomers of antiquity were. Eratosthenes, for example, who computed the size of the Earth from the different shadow lengths in 2 Egyptian cities.
It always makes me a little melancholy when he tells about the burning of the Library of Alexandria and all the information lost. It took mankind almost 2000 years to recover some of knowledge. What a waste because it was caused by rioting people, not a natural disaster.
Carl Sagan's use of a year's calendar to represent time since the Big Bang, humbles us as by representing "recorded history" as only a small slice of a few seconds at the end of the Cosmic Year. Now we're humbled in time as well as place (the Earth is only a dot in the vast universe).
There's a great moral at the end of the episode, don't swander our opportunity to acheive greatness by arguing amonst ourselves.