If Carl Sagan did not exist, some science-fiction writer would have to invent an astronomer like him to lay the groundwork for the first meeting between man and intelligent creatures from elsewhere in the universe. At 39, Sagan is America’s leading researcher in exobiology—the study of extraterrestrial life. He has received NASA’s Medal for Exceptional Scientific Achievement and the international astronautics prize, the Prix Galabert, for his studies of Mars using material gathered by Mariner 9. He designed the “message from Earth,” a kind of inter-galactic Esperanto made up of drawings and mathematical symbols, that was sent into space on Pioneer 10, the first spacecraft to leave the solar system.
Sagan is currently professor of astronomy and Director of the Laboratory for Planetary Studies at Cornell University. He has authored and co-authored a number of books on the origin of life and extraterrestrial life, the latest of which is The Cosmic Connection. Recently PEOPLE’S Ralph Novak asked him for a current report.
A couple of years ago you said that it was possible life existed elsewhere in the universe and we should accelerate our search for it. What has happened since then?
The idea of searching for that life has become somewhat more respectable, and there are now lots and lots of scientists who are urging us to undertake such a search. And our technical capabilities to make it have also substantially improved.
In what way?
We now know that we can land instruments on nearby planets. The Russians have done so on Venus, for instance, and are about to try instrument landings on Mars. And our radio astronomy capabilities are also much greater. We have the capability of communicating with a civilization on a planet orbiting around any one of 250 billion stars.
What are the chances for life on some of those other planets?
Even the interstellar medium—the very diffuse gas between the stars, a very hostile environment—is loaded with the simple molecular building blocks of life. This is a powerful discovery, suggesting that the chemistry necessary for the origin of life—as we know it—is common.
When you talk about other forms of life, what image do you see in your mind?
I don’t even try. Imagine yourself on Mars, viewing the Earth through a telescope and trying to figure out what the beasts of Earth are like. We are the way we are because of an enormous number of environmental crises that organisms dealt with one way and not another over millions of years.
Other forms of life wouldn’t be similar to us?
Even if you imagine the Earth beginning again, with purely random factors operating, such as a cosmic ray coming in to cause a mutation, I don’t think you’d wind up with life forms resembling anything that we have here today.
So if you consider another planet beginning with a quite different environment and evolving for billions and billions of years, you could expect it to produce creatures which are fundamentally different from organisms that are found on the Earth.
Could they fall within the bounds of what science-fiction people call “bug-eyed monsters”?
I suspect that bug-eyed monsters are much too close to human beings for any respectable extraterrestrial to look like that. There’s a kind of fatal lack of imagination in the conventional science-fiction image; it’s always a human being with a slight distortion, with those bug eyes, or antennae or colored green—very minor changes. Whereas I suspect they will have a whole organ system that we won’t have the foggiest notion of.
You talk about “human being chauvinism.” What do you mean?
The idea that extraterrestrial beings subject to perhaps four billion years of independent evolution would look approximately like us is a chauvinism. It says that there is something remarkably nice about human beings. And there is. But our design is not the only one possible for performing the tasks we do.
Doesn’t a lot of science-fiction encourage this kind of thinking?
Yes, and the classic science-fiction stories even have it that human beings can mate and produce viable offspring with beings of other planets. The fringiest part of the UFO fringe literature continues to have that idea, and there are reports—of course extraordinarily unreliable—of seduction and rape by extraterrestrials. I think the chance of a man mating with a petunia is much greater than the chance of him being able to mate, much less produce offspring, with an inhabitant of another planet.
Are you more optimistic about the possibilities of finding life in our own solar system than most scientists?
There are some who say they are positive there isn’t life anywhere else in the solar system, although I can never understand why. An environment like Mars or Jupiter or Saturn is a perfectly adequate one for life. We could invent ecological systems which would work perfectly well there. There’s certainly every reason to think that the steps that led to the origin of life in the early history of Earth were recapitulated in the early history of those planets. I don’t have a strong impression that there is life on Mars, and I don’t have a strong impression that there isn’t life on Mars. I have a strong impression it’s time to go and find out.
Is there any evidence so far that we have been visited by intelligent creatures from another planet, either from our solar system or another one?
The short and sweet answer is no. But in some ways I’m responsible for at least a bit of the furor over this subject. A book I did in 1966, Intelligent Life in the Universe, had a chapter examining the question of whether or not we had been visited in the past, looking at old legends and so on. I don’t believe there is any proof of that, but now this idea has been taken up in a way by Von Daniken in his book Chariots of the Gods? and by his imitators, and there’s clearly a great public desire to believe in this idea. Von Daniken says we have been visited; the UFO guys say we are being visited; the traditional religionists say we are going to be visited. And I’m not sure that there’s very much difference among the three points of view.
How would you expect such a visit to be made?
By a radio wave. It’s far and away the cheapest way to do it. It commits you the least.
You’re not a UFO believer?
If you really wanted to study UFOs, you would have to insist on tangible evidence and not be totally dependent on human testimony. But there are no close-up photographs that aren’t hoaxes, no spectroscopic identifications, no pieces of UFOs that have been reliably acquired. I would love for extraterrestrial beings to visit the Earth. But we can’t impose our wishes on nature; we have to discover what nature is teaching. I think what nature is teaching us about UFOs is that this is more a psychological than an astronomical phenomenon.
We don’t have to worry about being invaded by giant pods then?
Even if you imagine a more pessimistic scenario with real invaders from space, it’s far too late for us to hide. We’ve announced our presence, starting with large-scale use of television in the late 1940s. All of that radiation gets out of the Earth’s ionosphere and expands away from the Earth at the velocity of light. So some 30 light-years out, there is a spherical shell of radiation, expanding in space, which even a backward civilization should detect. And that wavefront contains what? Howdy Doody, Milton Berle, the Army-McCarthy hearings, all the other signs of high intelligence from the late ’40s and early ’50s. If there are beings on planets 30 light-years out in space, they should be discovering some very strange things have been happening on the Earth. If there is life out there, and we wonder why we haven’t been visited, maybe that explains it.
How do you think most people would react if contact were made with another civilization, even by radio?
I’ve talked about this with a lot of people, and the prevalent emotional reaction is curiosity. What would the beings be like? What would they say? What do they know? What’s their religion? What’s their music like? Each person has his own set of questions.
Some religious fundamentalists would be unhappy because the Bible doesn’t say anything about this. But most theologians are willing to accept the existence of life elsewhere, because from their point of view, it greatly expands the domain of God. The opposite is an extremely narrow vision of an all-powerful being who leaves a cosmos unpopulated and devotes his attention to one little hunk of rock and metal called the Earth.
How will life be different for us humans when we meet our cosmic neighbors?
I think the most significant change will be our perception of ourselves. What will be clear is that there are no human beings elsewhere—no beings biologically as close to us as the bacteria are, anywhere else in the cosmos. In that context, the differences among people on Earth will wither before our similarities.