At 60, celebrity stargazer Sagan sees to it that his universe keeps expanding

It was the stars, twinkling in the sky above Brooklyn where he grew up, that fired Carl Sagan's imagination when he was only 5 and started him on a course from which he has never wavered: to understand the heavens and to share the excitement of discovery with others.

The stars, Mr. Sagan said recently in an interview, "were clearly different from the rest of my environment, but when I asked people what they were, nobody knew.


"When I found out the stunning, stunning answer -- that the stars were suns, but so far away that they just appeared as these pale flickers of light -- the universe opened up to me. The scale, the immensity. I found it just dazzling."

He has never stopped looking and being dazzled, and in the decades since that early stargazing whetted his interest, Mr. Sagan has probably done more than any other living person to awaken a similar curiosity and excitement about the heavens among people around the world.


His book "Cosmos" is the best-selling English-language science book of all time. His "Cosmos" television series was the most-watched program in the history of the Public Broadcasting Service and has been seen by 500 million people in 60 nations. He is perhaps the best-known living scientist.

Last summer, he was awarded the Public Welfare Medal of the National Academy of Science, the group's highest honor, given to only about 10 people so far. In its citation, the academy said "no one has ever succeeded in conveying the wonder, excitement and joy of science as widely as Carl Sagan and few as well."

Ironically, the academy still has denied Mr. Sagan full membership, although he has been made an "honorary" member. Some members -- a number large enough to blackball him -- apparently feel that his popularizations of science have done a disservice to the profession, some scientists say, even though most scientists credit him with having dramatically boosted public understanding of science.

Philip Morrison, a distinguished physicist at the Massachusetts Institute of Technology, says, "We friends claim it was just plain envy."

Mr. Sagan, who turned 60 last month, shows no signs of slowing the rapid pace of his work in both research and the popularization of science. He is involved in a half-dozen research projects, has just released a new science book ("Pale Blue Dot") and is working on a novel (a love story). He also is working with his wife, Ann Druyan, on the screenplay for a movie (which will star Jodie Foster) based on his science-fiction novel "Contact."

"I like to do diverse things," Mr. Sagan said, "in part because if you're doing several things at once, if you get stuck on one, go on to the next. And then you find when you go back to the one you were stuck on, your unconscious mind has made enormous progress while you weren't looking."

While his interests, writing and research have ranged broadly, there is a theme to his work: Understanding, in the broadest sense, where we came from and determining whether other intelligent beings share the cosmos with us. (And, along the way, trying to ensure that humankind lasts long enough to find out.)

From the moment his interest in the stars was kindled as a child, Mr. Sagan says, he was seized by "the idea that most or all those stars had planets, and maybe even life. The possibilities that opened up -- it never occurred to me to do anything but try to find out about it.


"I thought I would have to have some job I hated -- a salesman in the coat and suit industry, for example, was proposed to me -- and then I'd pursue this weekends," he recounts. "The idea that I could be a professional astronomer, that there was such a thing, that they paid you enough to have three square meals and spend all your time studying this stuff -- that was a glorious discovery."

Not that it was easy at the beginning. As a student at the University of Chicago in the late 1950s, he had the good fortune to study under Gerard Kuiper, who at that time was the world's only full-time planetary scientist.

"I started well before Sputnik," the first satellite ever launched into orbit, in 1957, he said. "The idea of going to other planets, even the idea of studying other planets, was considered by many astronomers disreputable, fatally compromised by Percival Lowell," the Massachusetts astronomer who dedicated his life to studying the later-discredited "canals" of Mars and, to many people, left a lasting legacy of mistrust of the study of planets.

But Mr. Sagan says he was "ridiculously obdurate" and insisted on studying the planets anyway.

His wife at the time, Lynn Margulis, now a highly respected biologist at the University of Massachusetts-Amherst, says Mr. Sagan's abilities as a scientist and communicator were obvious even then. They met at the University of Chicago when she was 16 and he was 19, and already, she said, "there was no doubt about his promise and his intellectual and verbal abilities."

His doctoral thesis -- determining that the planet Venus is hellishly hot because of a runaway greenhouse effect caused by carbon dioxide in its atmosphere -- was an important breakthrough. It turned out to have great relevance to the continuing debate about whether burning fossil fuels on Earth could trigger global warming by the same mechanism.


Mr. Sagan went on to work on, and in many cases direct, the scientific research on most of the great missions of planetary exploration that took place during the 1970s and 1980s using robotic spacecraft, including the Viking mission to Mars and the Voyager visits to the outer planets. He continues to play a major role in planning for the two dozen U.S. and Russian spacecraft being prepared for visits to Mars over the next decade or so.

In 1980, worried that the National Aeronautics and Space Administration's (NASA) budget for exploration had been eaten up by the space shuttle program and that no new planetary missions were being planned, Mr. Sagan co-founded the Planetary Society with Bruce Murray, an astronomer at the California Institute of Technology and former director of NASA's Jet Propulsion Laboratory.

The society, which has 100,000 members and is the world's largest public organization devoted to space exploration, lobbies for increased funding and in some cases has directly funded planetary research.

While many scientists appreciate what he has done to publicize and promote their craft, others complain that his popularizations trivialize the field and that he too often strays outside his own areas of expertise and sometimes gets in over his head.

Dr. Morrison calls Mr. Sagan "a man full of force and integrity, even if he's not always right." But he says some scientists were put off because Mr. Sagan "was very conspicuous on television at a time when few of us did that kind of thing."

The frenetic pace of his work has had a cost. Of his five children from three marriages, the three oldest had little contact with their father while they were growing up, but he says his relationships with them have improved greatly since he married Ms. Druyan.


While he still sees his father as somewhat arrogant and says "he's basically been focused on his career forever," Dorion Sagan, 35, the oldest and a science writer himself, says they have become closer, and he found himself very moved at his father's 60th birthday banquet.