Carl Sagan was a 20th-century scientist born in 1934 in New York. He died on December 20, 1996, at the age of 62 from complications of pneumonia and a bone disease called myelodysplasia. Sagan had a varied education in several scientific fields including physics, astronomy, biology, and cosmology.  Sagan was instrumental in pioneering cooperation between scientists in different fields. He helped define two new fields of planetary science and exobiology.



Carl Sagan's biggest contribution to the world was his ability to explain science to the lay public. Many scientists, especially researchers, are not good at explaining their work outside of the scientific community. Sagan attributed his own unusually effective ability to communicate on such subjects to not being 'the most brilliant student.' There is no doubt Sagan was a very intelligent person, but he claimed that the 'most brilliant' absorb new concepts instantly and are not familiar with the process of understanding most people experience while building knowledge.

Carl Sagan Mickey Adair / Getty Images

Education and Academic Career

Sagan had broad intellectual interests. He earned several degrees throughout his education and had an extensive academic career.

  • Attended the University of Chicago on a scholarship in 1951
  • Received doctorates in astronomy and astrophysics in 1960
  • Two years at Berkeley and Sanford as a post-doctoral fellow in biology
  • Assistant professor of the Harvard College astronomy faculty
  • The position of David Duncan Professor of Astronomy and Director of the Laboratory for Planetary studies at Cornell University in 1968
  • Remained at Cornell until his death in 1996
academic background Carl sagen peterspiro / Getty Images


Carl Sagan was involved at the beginning of the American space program. He was a consultant to NASA in the 1950s and briefed the astronauts before the Apollo moon landing. Sagan promoted public and government excitement concerning space exploration, and he is credited with securing funding for the Galileo mission. Galileo was launched to investigate Jupiter and other celestial bodies in the solar system. NASA is currently constructing a laboratory and public gallery to improve collaboration in research and development between academia, industry, and other organizations. It is called The Sagan Center in honor of Carl Sagan's desire to spread knowledge, and it will be open to the general public.

NASA Carl da-kuk / Getty Images


The two Voyager spacecraft launched in 1977 each carried a gold-plated copper phonograph record known as the Golden Records. Carl Sagan led the committee to choose content for the Golden Records. They contain sounds and images portraying life on earth. The sounds came from nature, animals, music in several cultures, laughter, and spoken greetings in 55 languages. Sagan also included the inspirational quote "Per Aspera ad Astra" in Morse code. The quote means " through hardships to the stars."

voyager Carl NASA / Getty Images

Early Research

Astronomers believed Venus had an Earth-like climate until radio astronomy discoveries in the 1960s found that Venus was very hot surface. Sagan's early research and thesis included the first greenhouse model of the atmosphere. Sagan hypothesized that infrared opacity to carbon dioxide and water vapor produced surface temperatures hundreds of degrees higher than an airless planet. He expanded on his original research and was involved with NASA's Mariner explorations. The Mariner findings confirm Sagan's theories, and his models of Venus are still in use today. Sagan also developed theories on Mars and contributed to NASA's Viking explorations of the red planet.

research Carl adventtr / Getty Images


Carl Sagan did not believe UFOs were alien spacecraft. He had a thorough understanding of many explanations for unidentified aircraft and the reasons people mistakenly thought of extraterrestrials instead. Sagan held a symposium for The American Association for the Advancement of Science in 1969 to debunk UFO theories. He maintained that there was no evidence of extraterrestrial activity related to UFOs, but qualified his position slightly by allowing that evidence might be found. The concession came about because Sagan did not want to discourage believers from seeking more knowledge or prevent them from attending the symposium.

UFOs Carl ZargonDesign / Getty Images


Sagan's list of publications is over 250 pages long and his novel "Contact" became a hit movie. His passion was improving public understanding of science and promoting skepticism so everyone could recognize false claims or propaganda in commerce, politics, and science. Sagan believed scientists had a moral and ethical duty to address the public and confront false information directly. Despite his hard-line stance against pseudoscience, Sagan refused to participate in anything that demeaned religion or pseudoscientific beliefs. Sagan's rationale was that people do not learn through confrontation, and the goal of widespread understanding could not be achieved by winning a fight or alienating people.

publication Carl Santi Visalli Inc. / Getty Images


Sagan's television career started after he published "The Cosmic Connection.' He first appeared on The Tonight Show with Johnny Carson" in 1973 and appeared on the show 26 times in total. Sagan was very enthusiastic and often brought the latest photos from NASA missions. His popularity grew quickly. He presented a 13-episode television series Cosmos: A Personal Journey" written by Sagan, Anne Druyan, and Steven Soter. The show first aired on PBS in 1980. It is still the most-watched PBS series. As the series grew in popularity, it was purchased by other networks and sold as a VHS box set. The addition of new epilogues of Sagan discussing the latest discoveries and alternative viewpoints since the original broadcast prompted even more interest in the show.

tv Carl Schroptschop / Getty Images


The Sagan family were Reform Jews. Carl's father, Samuel Sagan, was an immigrant from part of the Russian Empire that is now Ukraine. Sagan's mother Rachel was a very devout woman from New York. Their two children, Carol and Carl, enjoyed a close relationship with each other and their parents. Sagan's thoughts on religion were heavily influenced by his parents. The family was poor and experienced hardship, but Samuel Sagan engaged in charitable activities and advocated for labor unions. Sagan discusses his mother in many of his books and believed his mother was a 'true genius" stifled by her religion, gender, and status as a housewife. Sagan claimed he was never an atheist, but he was skeptical towards organized religion and developed many of his own ideas.

religion Carl Santi Visalli Inc. / Getty Images

Personal Life

Sagan married three separate times, and has five children. Both of Sagan's ex-wives claimed that Carl's intense focus on his career and constant quest for knowledge led to absence from his family. Carl's third marriage to author Anne Druyan lasted over 20 years until his death. Druyan was much more involved in Sagan's work and intellectual pursuits than his first two wives. Druyan shared Carl's passion for social and political causes related to science. She was a writer for his documentary series, a co-author of many novels and other publications, and helped him work on the environmental appeal "Preserving and Cherishing the Earth."

personal life Carl Mickey Adair / Getty Images


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