Pale Blue Dot

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

Author: Carl Sagan

Publisher: Ballantine Books 1997 (First published: 1994)

ISBN: 9780345376596

Pages: 360

An impressive work by a renowned scientific mind that is also socially responsible. Carl Sagan is the epitome of the people-centric scientists who also foresaw the spurt in space exploration in the latter half of the last century. Nothing lighted up the society’s imagination like the daring attempts by two superpowers to outsmart each other in space science and technology. For once, the competition was a healthy one that spawned huge benefits to mankind. Though manned missions to outer-space are not cost effective as compared a robotic one, the sight of a few brave warriors smoothly sailing through the blackness of space to unknown worlds was exhilarating. The people, politicians and the bureaucracy were all mesmerized by the feat of man first setting foot on the moon. Continuing from this epochal event, Sagan speculates on the future of human species in space and addresses the issues that make it imperative for our society to expand its reach to other planets in the medium term and also to other stars in the long term.

Sagan was part of the NASA team associated with Voyager probes, which explored the worlds of the four outermost planets from Jupiter. He tells the thrilling story of Voyager 1, which was designed to photograph Jupiter and Saturn at close range. Chugging along with a radioactive plutonium based power source – since solar power would be too weak at such long distance from the sun – Voyager 1 was healthy enough in 1980 after its scheduled reconnaissance with Saturn, hardly three years after its launch. NASA decided to extend its working life to explore Uranus and Neptune as well. It did both splendidly and even the extended mission was complete. The author always wanted to take a picture of the earth from that distant vantage point. Many opposed the move, citing the motive as nothing related to science. But finally, Sagan had his way. Just before the radio technicians were to be shuffled out for other projects, the command to take a last photo of the mother plant was issued. So in 1990, Voyager 1 turned its cameras inward to from where it came from, taking care not to orient the highly sensitive optics towards the sun. The picture reached earth nearly five hours later. And it was worth the effort. Though nothing much could be discerned from the photograph, the presence of earth as a pale blue dot on the family portrait of the solar system fills one with awe and humility. That tiny speck of brightness fills us with elation at the technological prowess with which the instrument made by a bipedal ape could snap the shot and humility at the insignificance of it all. Sagan devotes a few chapters to drive the point home. Presenting a brief history of the origins of geocentrism, the author explains how religion exerts a decisive thrust in shaping the false idea of the earth being at the centre of the universe. Recent incarnations of geocentric models in the guise of the anthropic principle which states that the physical parameters of the universe would be somehow tuned for compatibility for the existence of life forms that inhabit the earth. Sagan’s refuting of the principle hits the bull’s eye with the picture of the pale blue dot. Much of the frame, except that tiny point, is empty and meaningless when viewed through the eyes of the anthropic principle. Life, then, should be treated as a rare coincidence in the history of the universe.

Having written this book in 1994, one might expect the content to be dated somewhat, considering the rapid progress usually associated with science and technology in every passing year. Sadly, this is not the case in interplanetary exploration. Sagan has obviously missed some probes sent later than the year of publication, but there are no path-breaking efforts on the part of any nation like the Apollo project which put men on the moon. The book explains the real significance of the race between two superpowers to safely land a human being on the earth’s natural satellite. Sagan comments that the project was conceived and run as a political program rather than scientific. The spinoffs expected from such a huge exercise employing cutting edge technology would surely be worth something militarily. At the same time, this program shifted the focus from military to the civilian level as far as the competition between the U.S and Soviet Union was concerned. The immense success – 12 Americans landed on the moon, and no other country has been able to replicate it – helped produce optimism about technology and enthusiasm for the future. U.S. touched greatness with the Apollo project. After the end of Cold War, funding to space programs dried up mainly because of the downgrading of high-profile strategic warfare in the list of priorities of rich nations. The people too, changed its mindset from appreciation of science to concerns about the mindless application of it. Global warming and ozone layer depletion were two prominent trouble spots on the industrial landscape when this book was going to press.

There exist a few people who question the utility of carrying out expensive space programs by Third World countries like India where a considerable segment of the society live below poverty line. They would challenge the justification for earmarking a portion of the budget on expensive scientific projects like the Mangal Yaan. The recurrent refrain is that this money should be spent on poverty eradication efforts, which also means that scientific research is a prerogative of the rich. But this logic is utterly flawed as this seeks to isolate the poor nations from the benefits accrued from new knowledge and materials that is a byproduct of the main program. Space exploration and study are not something rich nations do in their free time. The tear in the Ozone layer that wraps around the upper atmosphere and the discovery that chlorine-containing Freon is the reason for its depletion was identified only because the scientists were familiar with a similar phenomenon observed on the planet Venus. The problem could be identified in time only because we were ready for it. Similarly, human-induced warming of the planet as a result of Greenhouse gases like carbon dioxide was first observed and studied in Venus, whose surface temperature is high enough to melt many metals. Venus was turned into an inferno because of Greenhouse effect. We have developed software models to predict the temperatures of Venus correctly. When these models were run with the conditions obtaining on earth, the results suggest heating up of the planet. Here also, we were ready for identifying the problem in light of experience gained from the study of another planet’s atmosphere. But the author’s third idea about nuclear winter appears superfluous. There will be a cooling off of the atmosphere as a result of an all out nuclear war between the big nations. Five scientists, including Sagan himself, informed the political leadership about such a prospect in view of the data obtained from other planets. However, the contingency of a nuclear war is now abated and this point is not very convincing at present.

A sizable part of the latter half is devoted to speculations on colonizing other moons, planets themselves, asteroids and comets in the remote edges of the solar system and even interstellar space. Colonization of the solar system is optimistically estimated to take place by around the next century. Leaving the technologies aside, the imposing task of making the other worlds habitable – terraforming – is daunting. Venus, Mars and Saturn’s moon Titan are the likely candidates. Sagan puts forward reasons for convincing the public and the politicians to compel national governments to set apart large sums in their annual budget for space travel and exploration. Any reference to Sagan is bound to evoke memories of SETI (Search for Extra Terrestrial Intelligence) among readers. Not surprisingly, he devotes a few chapters to it, in which he tantalizingly states that he personally has come across eleven instances of detecting probable alien broadcasts through the analysis of data from a radio telescope devoted to SETI. The positive aspect attributed to conquest of other worlds and also to detecting the presence of other intelligent beings is that it is a global effort, as the difference between peoples of various nationalities is trivial as compared to the vast difference between us and them. The author also sounds a note of caution against the sophisticated and lethal technologies that are required for terraforming and moving around asteroids of deflect incoming comets falling into the hands of rogue states or psychic national leaders.

Reading the book after a lapse of two decades since its publication brings to light some points which have gone clearly out of date. Pluto was still a planet for Sagan, as the threat of CFCs for their ozone-depleting potential a burning issue. Confident predictions of large scale robotic or even manned space missions to Mars have not materialized by now, even though George Bush, while unveiling his plans for new space missions in 1989 predicted a football match in Mars by 2019. Sagan’s arguments in favour of SETI is forceful, but still not very convincing. References to the sighting of earth as a pale blue dot is the theme of the book, but not even a monochrome image of Voyager 1’s original photograph is included in the book. Perhaps this is good, as the image, which is accessible on the Internet, is so ordinary and featureless that we marvel at the amount of ideas Sagan had mined out of it. The book incorporates a nice set of references and a good index.

The book is highly recommended.

Rating: 3 Star