Cosmos: Chapter 5 - Blues for a Red Planet
This chapter discusses the planet Mars -- the history of thought about Mars, what we now know about it, and what the future may hold for "the Red Planet."
Sagan begins by recalling some of the notions that the human imagination has concocted with regard to Mars over the last hundred years. He mentions the 1897 H. G. Wells novel The War of the Worlds and the impact that it had on the public psyche. He also describes the work of Percival Lowell, who studied Mars throughout his life and popularized the notion that the surface of Mars was covered with an intricate network of canals. We learn that Lowell was inspired by an Italian astronomer named Giovanni Schiaparelli, who, in 1877, reported seeing "canali" on the surface of Mars, which in Italian means channels or grooves, but which "was promptly translated into English as 'canals', a word that implies intelligent design."
Lowell observed Mars for years in an attempt to prove the existence of the canals. Sagan summarizes Lowell's visions:
"Lowell believed he was seeing a globe-girdling network of great irrigation ditches, carrying water from the melting polar caps to the thirsty inhabitants of the equatorial cities. He believed the planet to be inhabited by an older and wiser race, perhaps very different from us. He believed that the seasonal changes in the dark areas were due to the growth and decay of vegetation. He believed Mars was, very closely, Earth-like. All in all, he believed too much."
Sagan explains that Lowell was quite wrong about many of his observations:
"The canals of Mars seem to be some malfunction, under difficult seeing conditions, of the human hand/eye/brain combination. ... Lowell always said that the regularity of the canals was an unmistakable sign that they were of intelligent origin. This is certainly true. The only unresolved question was which side of the telescope the intelligence was on."
Sagan gives a sentimental account of how, as a boy, he read "with breathless fascination the Mars novels of Edgar Rice Burroughs" and how he, along with many others, were influenced "to consider the exploration of the planets as a real possibility."
At this point in the television series, Sagan gives an account of the life and work of Robert Goddard, who did pioneering work in rocket science. [Sagan omits this discussion from the book because, as he explains in the introduction, there is a chapter devoted to Goddard in Broca's Brain.] Goddard was "inspired by Wells and Lowell to invent a machine that would voyage to the planet Mars. ... He invented the technologies that propel, stabilize and guide modern rockets." Sagan explains that, although Goddard was privately envisioning a mission to Mars, he publicly advocated only a mission to the moon because he felt that a Mars mission would be ridiculed.
Sagan then gives a detailed description of the Viking I and Viking II missions to Mars in which he was intimately involved. Over the course of 18 pages, Sagan describes the challenges that the Viking mission planners faced and the experiments that were conducted to study the air and soil for their chemical makeup and the possible existence of life. Sagan concludes that, "by the criteria established before launch, two of the three Viking microbiology experiments seem to have yielded positive results. ... But the situation is complex and the criteria of experimental success may have been inadequate. ... As the legacy of Percival Lowell reminds us, we can be fooled."
Sagan finishes the chapter by considering the question "what shall we do with Mars?" Sagan answers this question as follows: "If there is life on Mars, I believe we should do nothing with Mars. Mars then belongs to the Martians, even if the Martians are only microbes. ... However, suppose Mars is lifeless. ... Might we be able to live on Mars? Could we in some sense make Mars habitable?"
Sagan then explains the concept of terraforming -- using genetically engineered plants to melt the Martian polar ice caps, irrigate the soil, establish a deeper atmosphere and ozone layer, and raise the surface temperature. Sagan notes with irony that part of the irrigation effort would be the construction of canals:
"The power of Lowell's idea may, just possibly, make it a kind of premonition. His canal network was built by Martians. Even this may be an accurate prophecy: If the planet is ever terraformed, it will be done by human beings whose permanent residence and planetary affiliation is Mars. The Martians will be us."
Tom |
