Like Michael Faraday, Dr. Sagan was such a great showman of science only the difference is, Sagan's audience was bigger since his documentaries [primarily "the Cosmos"] was shown worldwide & it captivated millions! (Though Faraday may have done the same if he only lived in the 20th century where radio & TV are available.)

But aside from filmed documentaries, Dr. Sagan also wrote a lot of best-seller science books - not the Chemistry & Physics type used in schools, but pocket books that were New York Times "best sellers!" (Carl Sagan briefly wrote in one of his books about his pilgrimage to Westminster Abbey back in the early 80's.)