Pale Blue Dot: A Vision of the Human Future in Space

“There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.”

Sagan here is describing his response to the “pale blue dot” photograph taken by Voyager 1 in 1990. This quote, perhaps the most reprinted of Sagan’s career, captures his belief that journeying into space will provide the perspective we need to recognize that humans should work collectively to make the future a better place. Earth is a limited resource, and human misconceptions and self-serving actions are currently threatening our survival.

“After the Earth dies, some 5 billion years from now, after it is burned to a crisp or even swallowed by the Sun, there will be other worlds and stars and galaxies coming into being—and they will know nothing of a place once called Earth.”

The scale dramatized by the “pale blue dot” photograph and implied by any other image of the cosmos is often thought of as only spatial. The universe is huge and the distance between stars is almost inconceivable. But Earth, only 4.5 billion years old, is also insignificant in the context of time.

“Modern science has been a voyage into the unknown, with a lesson in humility waiting at every stop.”

Sagan uses “voyage” both literally, referring to explorations of the universe, and figuratively, meaning that modern science has been closing in on other kinds of frontiers, from biology to psychology. Before we confirm anything scientifically, humans tend to assume that which gives them a sense of importance. When science explains a mystery, humans often find they overestimated their importance.

“In each age the self-congratulatory chauvinisms are challenged in yet another arena of scientific debate—in this century, for example, in attempts to understand the nature of human sexuality, the existence of the unconscious mind, and the fact that many psychiatric illnesses and character ‘defects’ have a molecular origin.”

Chauvinism often relies on myths and nonscience to justify privileging one group over another. Scientific breakthroughs tend to strip away justifications for chauvinism. Though Sagan only discusses the misconceptions of past centuries, here he gestures to the fact this process is happening all the time, that chauvinism will always exist and then become challenged by some new science.

“We have not been given the lead in the cosmic drama.”

Astronomy has revealed to humanity that the universe, the Milky Way, and our solar system have been around for billions of years before we existed and will likely be around for billions of years after we no longer exist. In other words, we are not only not the center of the universe; we are bystanders and tagalongs to existence.

“If I had to judge, I would say that there’s no life on any of the worlds we’ve studied, except of course our own. But I might be wrong.”

After reviewing the successes of the Voyager missions (but their failure to locate life in our solar system), Sagan confesses that what we know so far suggests that no, there is no life in the solar system except on Earth. But he also repeats that final sentence, “But I might be wrong,” each time he suggests that there is no life. He is careful to always leave open the possibility.

“Someday, from observations of our planetary system or another, the news of life elsewhere may be announced over the morning coffee.”

Sagan occasionally digresses into imaginary futures, extrapolating his optimistic view of technology and space exploration to its logical next step. Sagan confesses that he believes that alien life exists; here, he images that someday the notion of life elsewhere will become quotidian.

“Have we destroyed ourselves since launching Voyager, they might wonder, or have we gone on to greater things?”

Sagan imagines a scenario where, instead of us finding intelligent life in the universe, intelligent life finds one of the Voyager probes as its flies through the Milky Way many centuries if not millennia from now. These aliens will likely have no way to confirm whether Earth is still there and whether humans still exist. Sagan’s question is meant for us: Will we unite and save Earth?

“It does no harm to the romance of the sunset to know a little bit about it.”

Responding belatedly to the writers he quoted in earlier chapters, Sagan argues that science does not necessarily lead humans toward feelings of meaninglessness. Here, after explaining the science of light, Sagan notes that sunsets are no less beautiful. Knowledge of something does not remove its power.

“But more important than any of this, Apollo provided an aegis, an umbrella under which brilliantly engineered robot spacecraft were dispatched throughout the solar system, making that preliminary reconnaissance of dozens of worlds. The offspring of Apollo have now reached the planetary frontiers.”

Sagan credits the Apollo missions for not only inspiring those who watched the Moon landing on television but also changing the course of space exploration. He argues that without Apollo capturing the world’s imagination, it is unlikely that NASA would’ve been able to get as many robot missions funded as they did. Sagan believes we need another mission like Apollo to reinvigorate space agencies across the world.

“The exploration of other worlds has opened our eyes in the study of volcanos, earthquakes, and weather. It may one day have profound implications for biology, because all life on Earth is built on a common biochemical master plan. The discovery of a single extraterrestrial organism—even something as humble as a bacterium—would revolutionize our understanding of living things.”

Sagan occasionally refers to the first principles of physics, meaning astronomical laws that are true everywhere, not only on Earth. Here, he refers to this universal set of rules as “a common biochemical master plan.” Unlike much of physics, we don’t know the first principles of life, and we likely won’t until it is discovered on another planet, under different circumstances from Earth.

“Especially with continuing investment in robotics and machine intelligence, sending humans to Mars can’t be justified by science alone.”

A large portion of Pale Blue Dot is occupied by the question of human versus unmanned space flight. While Sagan believes humans will eventually need to travel the solar system, for the most part he argues for robot missions over human ones due to cost and risk to life. That said, Sagan also believes in reasons for space travel beyond science, including the symbolic value of humans on the frontier.

“Nightly newscasts from another planet, with their revelations of new terrains and new scientific findings, would make everyone on Earth a part of the adventure.”

Sagan connects the people on Earth to space exploration in multiple ways. The main way is by arguing for what he calls the “social utility” of “vicarious exploration” (226). This democratizing view of vicarious exploration is accomplished by mass media—something that has seemed effective in the cases of the Moon landing and the “pale blue dot” photograph. Elsewhere, Sagan imagines the use of virtual reality.

“Projects that are future-oriented, that, despite their political difficulties, can be completed only in some distant decade are continuing reminders that there will be a future. Winning a foothold on other worlds whispers in our ears that we’re more than Picts or Serbs or Tongans: We’re humans.”

Sagan describes one of the theses of Pale Blue Dot: By imagining what human futures in space might look like, he is creating that future. On a larger and more realistic scale, space missions that have value only in the future—like a robot mission to Mars meant to do reconnaissance for a future human mission—and in that sense, they can implicate humans across generations into one participatory group.

“Exploratory spaceflight puts scientific ideas, scientific thinking, and scientific vocabulary in the public eye. It elevates the general level of intellectual inquiry […] It encourages us to address problems in other fields that have also never before been solved. It increases the general sense of optimism in society. It gives currency to critical thinking of the sort urgently needed if we are to solve hitherto intractable social issues.”

One of the benefits of space exploration, Sagan argues, is that it puts science in the public eye. It is perhaps a rose-colored view of how the media portrays space exploration, but a hopeful one. He suggests that the circulation of scientific ideas will lead to greater engagement with science more broadly. Sagan includes critical thinking and objective approaches to solving social issues.

“The most important step we can take toward Mars is to make significant progress on Earth.”

Sagan often invokes an idea of the frontier in which human exploration of new worlds will provide a transformative power to fix problems on Earth. However, he also occasionally mentions that space exploration should take a backseat to many of Earth’s problems. And a few times, he suggests that fixing some of the issues on Earth—both social and environmental—will lead us back to space.

“Since hazards from asteroids and comets must apply to inhabited planets all over the Galaxy, if there are such, intelligent beings everywhere will have to unify their home worlds politically, leave their planets, and move small nearby worlds around. Their eventual choice, as ours, is spaceflight or extinction.”

The threat of asteroids and comets is a universal phenomenon, not unique to Earth. Multiple times in Pale Blue Dot, Sagan states that humans will need to settle on other planets to survive. But by universalizing that sentiment, Sagan suggests that space exploration, and the political unification of a planet, is a universal condition for survival.

“Maybe it’s a long shot, but the discovery of extraterrestrial intelligence might play a role in unifying our squabbling and divided planet. It would be the last of the Great Demotions, a rite of passage for our species and a transforming event in the ancient quest to discover our place in the Universe.”

In Chapter 3, “The Great Demotions,” Sagan lists the belief that humans are the only intelligent life in the universe as likely not disprovable. Here in Chapter 20, he imagines what would happen if we could disprove that notion. Would a new understanding of humans as just one of the intelligent species, rather than the only one, change the way we behave toward each other?

“This is the first moment in the history of our planet when any species, by its own voluntary actions, has become a danger to itself—as well as to vast numbers of others.”

Technological advancement and the misuse of that technology—innocently perhaps, in the case of CFCs and early reliance on fossil fuels, but also less innocently, in our continued use of fossil fuels and development of weapons of mass destruction—has led us to an extraordinary moment in history: the first time a species can self-annihilate. Arguably, the 21st century will be the moment when the future of life on Earth is decided.

“This is the first time that (a) our exponentiating technology has reached the precipice of self-destruction, but also the first time that (b) we can postpone or avoid destruction by going somewhere else, somewhere off the Earth.”

By coincidence, or perhaps because the two situations are linked by their shared technologies, the moment when humans first become a threat to themselves is also the moment when they can start journeying to other planets. As Sagan writes, “our leverage on the future is high just now” (305). But also, because both repairing Earth’s atmosphere and settling other worlds will take generations of human time, decisions must be made soon.

“The more of us beyond the Earth, the greater the diversity of worlds we inhabit, the more varied the planetary engineering, the greater the range of societal standards and values—then the safer the human species will be.”

Sagan describes human survival as a question of statistics. As we know, there are multiple ways Earth and human settlements on other worlds might not survive: deterioration of the environment, self-destruction through war, and annihilation by asteroids or comets. Each of these scenarios can follow settlers to new worlds. Whether by luck or the eventual establishment of a culture based on scientific thinking, some settlements might continue.

“On behalf of Earthlife, I urge that, with full knowledge of our limitations, we vastly increase our knowledge of the solar system and then begin to settle other worlds.”

Throughout Pale Blue Dot, Sagan plays both sides of the argument, opting for a dialogical approach. Occasionally he says outright what he thinks. Here, in probably the strongest statement of the book on this subject, Sagan speaks directly to the reader in favor of increasing current space exploration efforts.

“Many of the dangers we face indeed arise from science and technology—but, more fundamentally, because we have become powerful without becoming commensurately wise. The world-altering powers that technology has delivered into our hands now require a degree of consideration and foresight that has never before been asked of us.”

Sagan acknowledges that human technological innovation is not all good news. He admits that we are innovating more quickly than we are considering the implications of the technologies. He seems to forget the nuclear bomb when he suggests that this degree of foresight is new, though he is correct that the “degree of consideration” is higher than ever.