The author of the book 'Pale Blue Dot' is Carl Sagan, a five-letter word. Sagan was an American astronomer, astrophysicist, cosmologist, author, and science communicator. He is best known for his work as a science popularizer and communicator, and he was also a highly successful author, writing several best-selling books. His most famous work, 'Pale Blue Dot', was published in 1994 and is considered one of the most influential works of popular science ever written. The book explores the history of the universe and humanity's place within it, and it has been credited with inspiring a generation of scientists.