Astronomer Carl Sagan: Influential Scientist and Public Educator

The Influential Astronomer Carl Sagan

While many scientists are natural teachers, few have been able to bridge the gap between research and public outreach like Sagan. He was a respected professor and author who made important contributions to the search for life beyond Earth.

His speculative nature-openly discussing the possibility of life on Mars, for example-disturbed some of his colleagues. He also valued proper recognition of other scientists, which is why his name came last in most of his publications.

Born in New York City

Sagan’s interest in science was piqued at an early age. He would read encyclopedias and learn everything he could about science, space and the stars. His parents recognized his talent and encouraged him to research answers to the many questions he had. He earned a number of scholarships and awards and graduated from Rahway High School with honors.

He authored more than two dozen books and was a frequent guest on television programs. His boyish good looks and resonant voice made him an effective public speaker and he was an expert at explaining complex scientific subjects in ways that were accessible to the general public. In 1980, he founded the Planetary Society, an organization that inspires and involves the public in the excitement of space exploration.

Educated at the University of Chicago

In the 1950s, the University of Chicago had a broad undergraduate curriculum that pushed students to explore a wide range of knowledge. Sagan benefited from this environment and later recalled that it made him a well-rounded thinker. He took courses in science, philosophy, and literature. He also read the classics, including Aristotle, Bach, Shakespeare, and Freud.

He wrote several papers on Venus, analyzing its atmosphere. His work led him to the idea that quasi-seasonal changes on the planet were caused by wind-blown dust. He was a pioneer in the study of exobiology, and believed that life could exist on other planets.

He also conceived of the universal message sent by the Voyager spacecrafts, which contained music and greetings in 59 languages. His work inspired a generation of scientists and popularized science for the masses.

Founded the Planetary Society

After his graduation from the University of Chicago with bachelor’s and master’s degrees, he began specializing in planetary science. In 1968 he became director of Cornell’s Laboratory for Planetary Studies and worked with NASA. He pioneered the study of life beyond Earth and promoted SETI, the search for extraterrestrial intelligence.

He authored numerous scientific papers and books and was also a host of the popular 1980 television series Cosmos. He was also a staunch advocate for nuclear disarmament and opposed the Strategic Defense Initiative of U.S. President Ronald Reagan.

Sagan believed that the cosmos was a fundamentally benign place, congenial to intelligent life. He was puzzled that we hadn’t yet made contact with an alien civilization, a problem known as the Fermi paradox.

Author of over two dozen books

While he wrote many scientific papers and books, Sagan achieved world fame as the host and writer of the 1980 television series Cosmos. He also was a highly respected professor at Cornell University and directed the Laboratory for Planetary Studies.

He and his team studied the physical conditions of planets. They modeled the atmosphere of Venus and concluded that its greenhouse effect was responsible for its extreme heat; they explained the quasi-seasonal changes on Mars as wind-blown dust; and investigated the composition of Jupiter’s atmosphere and helium rain.

One of his most influential works was The Cosmic Connection, in which he speculated that intelligent life exists elsewhere in the universe and that humans might eventually make contact with it. He was a tireless defender of rationality, and he opposed pseudoscience.

Television personality

Sagan’s encyclopedic knowledge, boyish good looks, and resonant voice made him a popular lecturer and TV personality. He authored several books and academic papers, but he also invested much of his career in improving public understanding of science and defending its rational nature against pseudoscience.

Sagan helped with many projects for the American space program, including the Mariner 2 mission to Venus; the Viking 1 and Viking 2 missions to Mars; and the Voyager 1 and Voyager 2 trips beyond the solar system. He was also a consultant and adviser to the Apollo astronauts before their flights.

Sagan also offered theories that would later be proven true, such as the belief that Jupiter’s moon Titan might contain oceans and that the shifting coloration of Mars was caused by windblown dust. He was a steadfast opponent of pseudoscience, which he thought it was the responsibility of scientists and scientific societies to expose.

Continue on this learning path