Carl Sagan's scientific legacy extends far beyond “Cosmos.”

On November 9, 2024, the world will rejoice Carl Sagan's ninetieth birthday – but unfortunately without Sagan died in 1996 on the age of 62.

Most people remember him as a co-creator and host within the Nineteen Eighties TV series “Cosmos”.seen by a whole lot of thousands and thousands of individuals worldwide. Others read “contact“, his best-selling science fiction novel, or “The Dragons of Eden“, his Pulitzer Prize-winning nonfiction book. Millions more saw him popularize astronomy on “The Tonight Show.”

What most individuals don't learn about Sagan, and what’s somewhat obscured by his fame, is the far-reaching impact of his scholarship, which continues to resonate today. Sagan was an unparalleled science communicator, astute advocate, and prolific author. But he was also an impressive scientist.

Sagan advanced science in at the very least three vital ways. He delivered remarkable results and insights that were described in over 600 scientific papers. It enabled the emergence of latest scientific disciplines. And he inspired several generations of scientists. As a planetary astronomerI consider that such a mixture of talents and achievements is rare and only happens once in a lifetime.

Scientific achievements

In the Nineteen Sixties little or no was known about it Venus. Sagan investigated how the greenhouse effect in its carbon dioxide atmosphere might explain Venus's unbearably hot temperature – about 870 degrees Fahrenheit (465 degrees Celsius). His research stays a cautionary tale concerning the Dangers of fossil fuel emissions here on earth.

Sagan proposed a compelling explanation for seasonal changes in Mars' brightness that were incorrectly attributed to vegetation or volcanic activity. There was dust blown by the wind responsible for the mysterious variationshe explained.

Sagan and his students studied how changes within the reflectivity of the Earth's surface and atmosphere affect our climate. They considered how the detonation of atomic bombs could release a lot soot into the atmosphere that it could cause significant cooling, a phenomenon that may last for years generally known as nuclear winter.

With unusual breadth in astronomy, physics, chemistry and biology, Sagan advanced the emerging discipline of astrobiology – the study of life within the universe.
Together with the researcher Bishun Khare At Cornell University, Sagan conducted groundbreaking laboratory experiments and showed that certain ingredients in prebiotic chemistry, called Tholinand certain constructing blocks of life, generally known as Amino acidsarise naturally in laboratory environments that mimic the planet's environments.

He also modeled the delivery of prebiotic molecules to the early Earth by asteroids and cometsand he was deeply involved within the biological experiments on board Mars Viking lander. Sagan also speculated on the likelihood that balloon-shaped organisms could float within the atmospheres of Venus and Jupiter.

His passion for locating life elsewhere reached far beyond the solar system. He was an advocate of the seek for extraterrestrial intelligence, also generally known as SETI. He helped with financing and took part in a scientific Search for alien beacons by scanning 70% of the sky with the physicist and electrical engineer Paul Horowitz.

He suggested it and helped shape it Plaques And the “golden records” now attached to humanity's most distant ambassadors, the pioneer And Voyager Spaceships. It is unlikely that aliens will ever find these artifacts, but Sagan wanted people to take into consideration the opportunity of communication with other civilizations.

Advocacy

Sagan's scientific achievements have consistently made him an eloquent advocate on problems with social and scientific importance. He testified about it before Congress Dangers of climate change. He was an anti-nuclear activist and spoke out against the Strategic Defense Initiativealso generally known as “Star Wars”. He pushed for collaborations and a joint space mission with the Soviet Unionin an try and improve relations between the United States and the Soviet Union. He spoke on to members of Congress concerning the seek for extraterrestrial intelligence and arranged one Petition signed by dozens of outstanding scientists I ask for help with the search.

But perhaps his most vital gift to society was his promotion of the seek for truth and significant pondering. He encouraged people to have humility and discipline to interact with their most cherished beliefs—and to depend on evidence to form a more accurate picture of the world. His most quoted book: “The Demon-Haunted World: Science as a Candle within the Dark“is a helpful resource for anyone attempting to navigate this age of disinformation.

Effects

A scientist's influence can sometimes be measured by how often his or her scientific work is cited by other scientists. Accordingly Sagan's Google Scholar pagehis work continues to be cited greater than 1,000 times every year.

In fact, its current citation rate exceeds that of many members of the National Academy of Scienceswhich, in response to the academy's website, is “elected by its peers for outstanding contributions to research” and is “one of the highest honors a scientist can receive.”

Sagan was nominated for election to the Academy within the 1991–1992 cycle, but his nomination was challenged on the annual meeting; greater than a 3rd of members voted to maintain him out, which doomed his approval to failure. An observer of this meeting wrote to Sagan: “It is the worst of human weaknesses that keeps one from doing so: jealousy.” This belief was confirmed by others present. In my opinion, the Academy's refusal to simply accept Sagan stays a long-lasting stain on the organization.

No amount of jealousy can diminish Sagan's deep and far-reaching legacy. In addition to his scientific achievements, Sagan has inspired generations of scientists and instilled an appreciation for science in countless non-scientists. He has shown what is feasible within the areas of science, communication and advocacy. These achievements required truth-seeking, labor, and self-improvement. As Sagan celebrates his ninetieth birthday, a renewed commitment to those values ​​would honor his memory.