Pale Blue Dot - Carl Sagan [81]
Nuclear winter was first calculated and named in 1982/83 by a group of five scientists, to which I’m proud to belong. This team was given the acronym TTAPS (for Richard P. Turco, Owen B. Toon, Thomas Ackerman, James Pollack, and myself). Of the five TTAPS scientists, two were planetary scientists, and the other three had published many papers in planetary science. The earliest intimation of nuclear winter came during that same Mariner 9 mission to Mars, when there was a global dust storm and we were unable to see the surface of the planet; the infrared spectrometer on the spacecraft found the high atmosphere to be warmer and the surface colder than they ought to have been. Jim Pollack and I sat down and tried to calculate how that could come about. Over the subsequent twelve years, this line of inquiry led from dust storms on Mars to volcanic aerosols on Earth to the possible extinction of the dinosaurs by impact dust to nuclear winter. You never know where science will take you.
PLANETARY SCIENCE fosters a broad interdisciplinary point of view that proves enormously helpful in discovering and attempting to defuse these looming environmental catastrophes. When you cut your teeth on other worlds, you gain a perspective about the fragility of planetary environments and about what other, quite different, environments are possible. There may well be potential global catastrophes still to be uncovered. If there are, I bet planetary scientists will play a central role in understanding them.
Of all the fields of mathematics, technology, and science, the one with the greatest international cooperation (as determined by how often the co-authors of research papers hail from two or more countries) is the field called “Earth and space sciences.” Studying this world and others, by its very nature, tends to be non-local, non-nationalist, non-chauvinist. Very rarely do people go into these fields because they are internationalists. Almost always, they enter for other reasons, and then discover that splendid work, work that complements their own, is being done by researchers in other nations; or that to solve a problem, you need data or a perspective (access to the southern sky, for example) that is unavailable in your country. And once you experience such cooperation—humans from different parts of the planet working in a mutually intelligible scientific language as partners on matters of common concern—it’s hard not to imagine it happening on other, nonscientific matters. I myself consider this aspect of Earth and space sciences as a healing and unifying force in world politics; but, beneficial or not, it is inescapable.
When I look at the evidence, it seems to me that planetary exploration is of the most practical and urgent utility for us here on Earth. Even if we were not roused by the prospect of exploring other worlds, even if we didn’t have a nanogram of adventuresome spirit in us, even if we were only concerned for ourselves and in the narrowest sense, planetary exploration would still constitute a superb investment.
CHAPTER 15
THE GATES OF THE WONDER WORLD OPEN
The great floodgates of the wonder-world swung open.
—HERMAN MELVILLE, MOBY DICK, CHAPTER 1 (1851)
Sometime coming up, perhaps just around the corner, there will be a nation—more likely, a consortium of nations—that will work the next major step in the human venture into space. Perhaps it will be brought