Carl Sagan is best known as a science popularizer, but he was also a renowned pioneer in the early US space program, a planetary scientist, astrobiologist, Pulitzer Prize-winning author, and social activist. Now a major archive of his work preserved by his assistant Shirley Arden is going on sale via Boston-based R R Auction – a collection that provides new insights into the life and works of this remarkable man.

Mention Carl Sagan and most people will recall him as the host of the award-winning Cosmos documentary series from the 1980s or from his catch phrase, "billions and billions." But the Cornell professor who passed away in 1996 from pneumonia as a complication of myelodysplasia had a far more diverse career than many of today's generation realize.

Beyond his television appearances, Sagan was the author of a number of books popularizing science, but he was also a major figure in many fields of research. It was a combination that made him a controversial figure among his peers, who couldn't decide if he was a polymath with a gift for public education, or a self-aggrandizing gadfly who couldn't settle down to serious work.

During his life, Sagan acted as a consultant to NASA, provided briefings to the Apollo astronauts, was involved in a secret US project to explode a nuclear bomb on the Moon, an early experimenter in how life might have arisen on the Earth, and a major figure behind the unmanned Mariner, Viking, Voyager, and Galileo planetary expeditions. In addition, he created the first physical messages sent into space in hopes of contacting an alien civilization.

While the vast majority of Sagan's papers, numbering 595,000 items, are archived at the US Library of Congress, Another major source is the personal collection of books and office papers retained by Shirley Arden, who acted as Sagan's assistant from 1974 into the 1980s, when he was co-writing and presenting the Cosmos series and working on the Voyager mission at the Jet Propulsion Laboratory in Pasadena, California.

According to RR Auctions, the office documents, which include Arden's notebook of correspondence with Keay Davidson, were exclusive primary sources for Davidson's 2000 biography of Sagan.

The collection, which includes 20 items signed by Sagan, consists of hundreds of pages of office papers, notes handwritten by Sagan, letters, cards, photographs, books, pamphlets, and slide lectures. One item of particular interest is a letter handwritten and signed by Sagan in about 1980 on paper with the Cosmos letterhead, which Sagan refers to as "this somewhat gaudy stationery."

In addition, there are three books signed by Sagan, including a first edition of Cosmos, file folders from 1975 to 1981 containing hundreds of pages of notes and memoranda, call logs, daily schedules, and work summaries. Photographs include publicity stills from the series as well as 200 NASA images from the Voyager and Viking missions. There are also press kits, rough drafts of a never produced television series called Nucleus, and typescripts for articles by Sagan.

"As a whole, this is a historically significant archive stemming from one of the most exciting periods in the history of modern astronomy," says Bobby Livingston, Executive VP at RR Auction. "Sagan effectively bridged the gap between academics and popular culture."

The Carl Sagan Archive is part of the Fine Autographs and Artifacts Auction at RR Auction that runs until June 14.

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