10 Cool Things About Carl Sagan

By: Laurie L. Dove  | 
Carl Sagan
Carl Sagan received a Ph.D. in astronomy and astrophysics. Tony Korody/Sygma via Getty Images
Key Takeaways
  • Carl Sagan, a renowned astronomer and science communicator, popularized the study of the cosmos with his enthusiasm and accessible explanations.
  • He contributed significantly to our understanding of planetary science, advocating for the exploration of Mars and other celestial bodies.
  • Sagan's legacy lives on through his books, such as "Cosmos," and his iconic phrase "billions and billions," which continues to inspire curiosity about the universe.

Before Neil deGrasse Tyson, there was Carl Sagan. Handsome, articulate and witty, Sagan wasn't a man about town. He was a man about the cosmos. A tireless proponent of the universe, he was a pioneer in bridging the gap between science and nonscientists.

Sagan was a giant among his peers, too. He received 22 honorary degrees from colleges and universities throughout the U.S., published more than 600 scientific papers and articles, wrote best-selling books and hosted a record-breaking public television series, "Cosmos: A Personal Voyage." He discovered that Venus was heated through the greenhouse effect (something scientists later learned also happens on Earth) and that the red color of Mars comes from windstorm dust rather than vegetation. NASA explorations eventually proved he was right.


Sagan was born in 1934 and grew up in Brooklyn, New York. He graduated from the University of Chicago in 1960 with a doctorate in astronomy and astrophysics, then taught at Harvard and Cornell, where he became the director of Cornell's Laboratory for Planetary Studies and the David Duncan Professor of Astronomy and Space Sciences.

Some of Sagan's most memorable contributions occurred outside the classroom. During the 1950s and 1960s, he was NASA's astronaut whisperer. He offered advice to the Apollo crew before their journeys to the moon and conceived experiments for other planetary expeditions, including an interstellar record designed to greet the unknown inhabitants of deep space. And that's just one cool thing on our list.

10: Hosted Public Television's Most-watched Show

Carl Sagan
Carl Sagan co-developed and hosted the hit PBS show "Cosmos: A Personal Voyage." Tony Korody/©Tony Korody/Sygma/Corbis

Once described by a critic as a "scientific Robert Redford," Carl Sagan codeveloped and hosted the hit show "Cosmos: A Personal Voyage," a 13-part series that originally aired in 1980 on PBS. For 10 years, it was the channel's most-watched show in the U.S. until "The Civil War."

"Cosmos: A Personal Voyage" was a perfect blend of science and simplicity. It showcased Sagan's ability to explain complex principles in a way that viewers could easily understand. Sagan had envisioned a scientific series that harnessed TV's visual power, and with an $8 million production budget to power an array of special effects, he soon had viewers zipping through the universe on a virtual spaceship.. The series won three Primetime Emmy Awards, a Hugo Award and a Peabody Award in 1981 [source: IMDB].


The show won over millions of viewers, too. Thanks to 500 million fans tuning in from 60 different countries, "Cosmos" still reigns as the world's most-watched series from American public television.

9: Never Said His Famous Catchphrase

Carl Sagan
Here during a 1979 press conference at MIT, Carl Sagan gives his views about the Voyager Golden Records, which were included aboard both Voyager spacecrafts. JP Laffont/©JP Laffont/Sygma/Corbis

When Carl Sagan said "billions" during the 13 episodes of "Cosmos: A Personal Voyage," viewers knew it. His overemphasis of the "b" in "billions" was deliberate; to make sure the word was not mistaken for "millions." Still, he never uttered the catchphrase "billions and billions."

It was Johnny Carson, host of "The Tonight Show," who cemented Sagan's relationship with "billions and billions" of galaxies. Sagan appeared as a show guest more than two dozen times, and Carson's popular impersonation of him repeating the phrase, made a lasting impression — one Sagan was never able to shake. It was copied by other comedians and satirized in a Frank Zappa song.


In Sagan's (perhaps sarcastically titled) book, "Billions and Billions," he wrote, "Oh, I said there are maybe 100 billion galaxies and 10 billion trillion stars. It's hard to talk about the Cosmos without using big numbers ... But I never said 'billions and billions.' For one thing, it's too imprecise ... For a while, out of childish pique, I wouldn't utter or write the phrase even when asked to. But I've gotten over that. So, for the record, here goes: 'Billions and billions.'"

8: Tried to Have Marijuana Legalized

Carl Sagan
Carl Sagan was a lifelong user of, and advocate for, marijuana. Curi Hyvrard / © Curi Hyvrard/Corbis

Perhaps taking the meaning of "high in the sky" to another level, Sagan secretly (then not-so-secretly) advocated that marijuana use was beneficial. In an essay he authored in 1969 at age 35 under the name "Mr. X," Sagan outlined marijuana's positive effects on his sensibilities. Marijuana, wrote Sagan, made music, art, food and sex better [source: Wing].

It wasn't until three years after Sagan's 1996 death that the author of "Carl Sagan: A Life" revealed him as the author of the pro-pot post. However, Sagan had already revealed himself as a marijuana advocate years earlier. During at least one interview, Sagan said he supported the legalized use of marijuana by the terminally ill.


"Is it rational to forbid patients who are dying from taking marijuana as a palliative to permit them to gain body weight and to get some food down? It seems madness to say, 'We're worried that they're going to become addicted to marijuana.' There's no evidence whatever that it's an addictive drug, but even if it were, these people are dying," Sagan said. "What are we saving them from?"

7: Crafted a Universal Message to Aliens

Pioneer 10
This artist's rendering shows Pioneer 10, an American Spaceprobe launched in 1973. Should it reach another galaxy and be found by other intelligent beings, it carries a plaque designed by Carl Sagan to identify humans on Earth as its source. ©Bettmann/CORBIS

In 1977, two NASA spacecraft left Earth's orbit to afford scientists a closer look at Jupiter and Saturn. And then these celestial-bound twin craft did something even more extraordinary: They transported our message to the universe.

The spacecraft were part of the Voyager Interstellar Mission, and each carried a gold-plated disc designed to survive for a billion years in the hopes an alien civilization might receive it as a greeting. The recorded sounds spanned many possibilities, including the first words uttered to a newborn, greetings in 59 different languages, and music from new and ancient civilizations.


It was Sagan who came up with the idea to add a message to the universe, a "bottle cast into the cosmic ocean," as he put it. Although Sagan's voice isn't heard on the record, he was certainly a part of its creation.

The recording also captured one of science's most famous love stories, the one between Sagan and the project's creative director, Ann Druyan. Next, we'll discuss how their personal voyage began with this interstellar one [source: Krulwich].

6: Became Engaged to Third Wife Before Their First Date

Carl Sagan and Ann Druyan
Carl Sagan and his then-fiancé Ann Druyan are seen here at the New York City Waldorf-Astoria circa 1980. Bettina Cirone/IMAGES/Getty Images

It was the summer of 1977, and Sagan's newest brainchild was coming to life. For months, he and Ann Druyan — a writer and producer working as the Voyager recording's creative director — had been amassing a very special collection. They were creating a cosmic mix tape, a recorded greeting for the universe that would be dispatched with the Voyager 1 and Voyager 2 space missions.

But it wasn't until Druyan discovered just the right Chinese melody — a 2,500-year-old song called "Flowing Stream" — that she and Sagan discovered their love for each other. Thrilled with her find, Druyan telephoned Sagan with the news, but was forced to leave a message. When he returned her call, they were on the phone for an hour. And by the time they said their goodbyes, they were engaged to be married — with nary a first date between them.


The sensation of falling in love was so strong, Druyan had the electrical impulses of her brain and nervous system recorded so that it could be turned into music and placed on the Voyagers' recorded greeting when the spacecraft were launched into space on Aug. 20, 1977.

In 1981, Sagan and Druyan were married, and remained together until Sagan's death 15 years later [source: Krulwich].

5: Mentored Neil deGrasse Tyson

Neil deGrasse Tyson.
Astrophysicist Neil deGrasse Tyson credits Carl Sagan for inspiring him as a young college student when Sagan was a professor at Cornell University. Amanda Edwards/Getty Images

What may seem simple to one person often becomes profound to another. Neil deGrasse Tyson, the quick-witted astrophysicist well known for hosting the 2014 version of the "Cosmos" series, received some valuable life lessons from Sagan as a high school senior.

Back on Dec. 20, 1975, Tyson traveled by bus from New York City to Cornell University to meet Sagan. A busy author, astronomer and professor, Sagan had personally extended Tyson an invitation to visit after seeing his college application to Cornell, where he spoke about his enthusiasm for the stars.


"I already knew I wanted to become a scientist," Tyson would later say, "but that afternoon I learned from Carl the kind of person I wanted to become."

After the personal tour of his lab, Sagan dropped Tyson off at the bus depot. As the snow was getting heavier, he told Tyson to call him if the bus was delayed so he could spend the night at his house.

Although Tyson opted to attend Harvard for his undergraduate education, Sagan's influence remained strong.

"To this day," Tyson said during an interview, "I have this duty to respond to students who are inquiring about the universe as a career path, to respond to them in the way that Carl Sagan had responded to me."

4: Made Turtlenecks His Signature Look

Carl Sagan
Carl Sagan wears one of his trademark turtleneck sweaters in a laboratory at Cornell University in Ithaca, New York in the '70s. Santi Visalli Inc./Getty Images

In March 2014, the "Cosmos: A Spacetime Odyssey" exhibit opened at the National Geographic Museum in Washington, D.C. The display showcased clips from the show reboot, as well as memorabilia from current host, Neil deGrasse Tyson, and original host, Carl Sagan. Among the items was an article so iconic, it is forever linked to Sagan's persona: one of his signature turtlenecks.

While Sagan did wear a variety of clothing on "Cosmos: A Personal Voyage," he became as known for sporting a turtleneck, topped with a professorial blazer, as for his passion about the universe. On Carl Sagan Day, an unofficial annual holiday on Nov. 9, the anniversary of his birth, Sagan fans are encouraged to wear a turtleneck sweater with a brown jacket — and to "celebrate the beauty and wonder of the cosmos he so eloquently described" [source: National Today].


3: His Work Was Preserved by a Cartoonist

Seth MacFarlane and Ann Druyan
Writer, producer and director Seth MacFarlane and author and producer Ann Druyan attend a Celebration Of Carl Sagan at The Library of Congress Nov. 12, 2013 in Washington, D.C. Paul Morigi/Getty Images

When Sagan died of pneumonia while battling bone marrow disease in 1996, he left behind a vast library of his life's work in the home he and his family live in during the 1980s.

The home was in upstate New York, near Cornell, and had once been headquarters to a secret society at the university known as the Sphinx Head Tomb. Later, the Sagans moved to a bigger house but kept the former Sphinx Head Tomb as a space for he and Druyan to collaborate on projects. When Sagan got ill, it became a catchall for his scientific papers, idea-filled notes, photographs and sketches — some dating back to his boyhood. "Thousands of individual items, boxed away in 18-foot-high filing cabinets," Sagan's daughter, Sasha, would later write [source: Sagan].


Druyan sought out colleges and institutions to preserve the collection, but none could provide the mix of meticulous care and thoughtful exhibition she had in mind. Then she met Seth MacFarlane, creator of the "Family Guy" cartoon. As the two began to collaborate on a reboot of Sagan's original "Cosmos" series, MacFarlane was instrumental in preserving Sagan's legacy — all the contents of the Sphinx Head Tomb — in the Library of Congress.

The Seth MacFarlane Collection of the Carl Sagan and Ann Druyan Archive opened to the public at the Library of Congress in Washington, D.C., in November 2013, the same month Sagan would have celebrated his 79th birthday [source: Sagan].

2: Sued Apple for Using His Moniker as a Code Name

Carl Sagan
In addition to his other activities, Carl Sagan was also an anti-nuclear weapon advocate. Here, he speaks at the Great Peace March in Washington, D.C., 1986. Joseph Sohm/©Joseph Sohm/Visions of America

Apple engineers, fond of code names, in 1994 dubbed the Power Macintosh 7100 "Carl Sagan" in reference to Sagan's supposed catchphrase, "billions and billions." The computer would make "billions and billions" of dollars for Apple, they hoped.

But this internal code name rubbed Sagan the wrong way. He worried that if news of the code name leaked to the public, it could be misconstrued as an endorsement. Sagan fired off a letter to Apple, insisting the company change the code name. Apple's engineers were quick to comply. They switched the code name to BHA, an acronym for "butt-head astronomer."


The move prompted Sagan to sue for libel; the case was dismissed, with the judge writing that "one does not seriously attack the expertise of a scientist using the undefined phrase, 'butt-head.'"

Sagan sued a second time, lost and began a lengthy appeal process. Sagan and Apple settled the suit in 1995. Apple engineers then changed the code name to LAW, for "lawyers are wimps."

Despite its string of code names, the 7100 never did make billions [sources: Davidson, Heisler].

1: Has an Asteroid Named After Him

Carl Sagan drawing
This Sagan drawing in just one example of some of the pieces that are part of The Seth MacFarlane Collection of Carl Sagan and Ann Druyan Archive at the Library of Congress. Paul Morigi/Getty Images

On Nov. 9, 1994, Carl Sagan turned 60 and his friends in the Cornell Astronomy Department hosted a party in his honor. There were speeches by loved ones, colleagues and former students, and letters from people like the late science fiction writer Arthur C. Clarke and then-vice president Al Gore.

The highlight, however, was a surprise announcement by Eleanor Helin, who was an expert at discovering asteroids: Her most recent finding, asteroid 4970, had been named "Asteroid Druyan."

The asteroid, named after Sagan's wife, Ann Druyan, was locked in an eternal orbit with another notable heavenly body: "Asteroid 2709 Sagan," the asteroid already named for Sagan [source: Spangenburg]. This was a wonderful birthday present and expression of love.

On a more humorous note, scientists have paid tribute to Sagan's deathless phrase "billions and billions," by naming a unit of measurement after him. The sagan is a number equal to at least 4 billion [source: Know Your Meme].

Frequently Asked Questions

Did Carl Sagan have any controversies or criticisms in his career?
While Carl Sagan was widely celebrated for his contributions to science communication, some critics questioned his involvement in public policy debates, particularly regarding nuclear winter theory and extraterrestrial life.
What impact did Carl Sagan have on popular culture beyond his scientific achievements?
Carl Sagan's influence extended into popular culture through his numerous appearances on television, including hosting the acclaimed series "Cosmos," and his role in the Voyager Golden Record, which carried messages from Earth into space.

Lots More Information

Author's Note: 10 Cool Things About Carl Sagan

Carl Sagan accomplished so much, it's difficult to think this top 10 list can do justice. Sagan fans are sure to read this and wonder why their favorite details of his life are not listed. Be gentle. It would have required a voluminous tome to capture the facts -- and nuances -- of Sagan's well-lived life. My attempt may not have been not exhaustive, but it was done in a spirit of discovery I think Sagan would have appreciated.

Related Articles

  • Center for Inquiry. "Carl Sagan Day." (April 26, 2014) http://www.centerforinquiry.net/carlsaganday
  • Davidson, Jacob. "Apple vs. Carl Sagan." Time magazine. July 10, 2013. (April 26, 2014) http://business.time.com/2013/07/10/isued-apples-greatest-legal-battles/slide/apple-vs-carl-sagan/
  • Heisler, Yoni. "When Carl Sagan Sued Apple...Twice." TUAW. Feb. 26, 2014. (April 26, 2014) http://www.tuaw.com/2014/02/26/when-carl-sagan-sued-apple-twice/
  • IMDb. "Cosmos." (April 26, 2014) http://www.imdb.com/title/tt0081846/awards?ref_=tt_awd
  • Kiger, Patrick. "Carl Sagan and the Cosmos Legacy." (April 26, 2014) http://channel.nationalgeographic.com/channel/cosmos-a-spacetime-odyssey/articles/carl-sagan-and-the-cosmos-legacy/
  • Know Your Meme. "Carl Sagan." (April 25, 2014) http://knowyourmeme.com/memes/people/carl-sagan
  • Krulwich, Robert. "Carl Sagan and Ann Druyan's Ultimate Mix Tape." NPR. Feb. 12, 2010. (April 25, 2014) http://www.npr.org/2010/02/12/123534818/carl-sagan-and-ann-druyans-ultimate-mix-tape
  • National Geographic. "New Exhibition, 'Cosmos: A Spacetime Odyssey,' to Open March 4 at National Geographic Museum." Feb. 28, 2014. (April 25, 2014) http://press.nationalgeographic.com/2014/02/28/exhibition-cosmos-a-spacetime-odyssey-museum/
  • Sagan, Carl. "Billions and Billions: Thoughts on Life and Death at the Brink of the Millennium." Random House. July 6, 2011. (April 26, 2014) http://books.google.com/books?hl=en&lr=&id=bPWy5ta4lM0C&oi=fnd&pg=PR11&dq=related:qvr6xCqxL8ZUSM:scholar.google.com/&ots=2_7hK67e9F&sig=_NVYe_yYWMCGxI89o2M8Rm92SOo#v=onepage&q&f=false
  • Sagan, Sasha. "Lessons of Immortality and Mortality From My Father, Carl Sagan." New York Magazine. April 14, 2014. (April 25, 2014) http://nymag.com/thecut/2014/04/my-dad-and-the-cosmos.html
  • Spangenburg, Ray. "Carl Sagan: A Biography." Greenwood Publishing. Jan 1. 2004. (April 26, 2014) http://books.google.com/books?id=Z01FzDkprgUC&pg=PA113&lpg=PA113&dq=sagan+asteroid+2709&source=bl&ots=8QO7RVQTYb&sig=k3P0UR9i19gcR7BBe9OHvbqKgXg&hl=en&sa=X&ei=Rp9fU77lFoqbyASyk4CwAw&ved=0CFEQ6AEwBw%23v=onepage&q=sagan%20asteroid%202709&f=false#v=snippet&q=sagan%20asteroid%202709&f=false
  • Welsh, Jennifer. "Neil deGrasse Tyson Describes His Life-Changing First Encounter with Carl Sagan." Business Insider. March 9, 2014. (April 25, 2014) http://www.businessinsider.com/young-neil-degrasse-tyson-met-carl-sagan-2014-3
  • Wing, Nick. "Carl Sagan, Marijuana Advocate, Explains What It's Like to Be High While Carl Sagan." Huffington Post. May 31, 2013. (April 26, 2014) http://www.huffingtonpost.com/2013/05/31/carl-sagan-marijuana_n_3367112.html