#98 September 1996
Section 188.8.131.52.098.of the Artemis Data Book
Tuesday, August 6th, 1996 will be a day most of us will never forget. Without prior warning or anticipation, it was leaked to the media that the next day, NASA would announce the finding of convincing evidence that Mars once harbored indigenous life.
For a century, Mars has been the favorite object of public and private celestial curiosity. Like Earth, it had polar caps, an atmosphere, and underwent obvious seasonal changes. Writer Edgar Rice Burroughs and astronomer Percival Lowell fed the public imagination with vivid pictures of a still living but dying planet, its once verdant life heroically clinging to an dwindling but industriously husbanded supply of water.
As pre-space age astronomers learned more and more about the red planet, however, it became harder and harder to cling to such visions. The atmosphere was tenuous at best, and we detected no oxygen or water vapor. It was argued that the polar caps were composed of frozen carbon dioxide (we now know that at least the north polar cap is principally water ice). The crushing blow was Carl Sagan's conclusion that the vaunted seasonal changes, a noticeable springtime darkening of sizable patches and strips advancing from the polar regions towards the equatorial regions, could be explained simply and elegantly (Occam's razor!) as fields of dust being rearranged by the planet's trade winds. In one fell swoop, life was no longer the obvious explanation, but just a relic of unsupported faith.
Then a series of NASA probes revealed a harsher, drier, crater-pocked, and ultraviolet-washed world than even the most pessimistic had imagined. The atmosphere, mostly carbon dioxide, was less than a hundredth of our own in surface pressure. A dying Martian race and canal-hugging crops long evaporated from public musings, even hoped for patches of lichen and other hardy but visualizable plants joined the growing list of dashed dreams for a sister world harboring life.
To be sure, follow-up probes revealed all but incontrovertible evidence of a once much wetter and warmer Mars, and a Mars with a thicker atmosphere. We found shorelines of an ancient northern ocean, river beds and flood channels and riverine islands, features for which there was no other equally plausible explanation. Evidently, Mars had evolved in parallel with Earth its first billion years before the consequences of its lesser endowments became inexorably more evident. In comparison with our own cradle planet, Mars has smaller mass (10%) and lighter gravity (38%) and lies significantly farther from the Sun (so that it receives only 38%-52% as much solar warmth as Earth, without Earth's 50 degF benefit from its oceanic heat sink). As the atmosphere thinned and surface waters evaporated (the vapor disassociating with the hydrogen escaping to space), all that remained was a dessicated surface ever more exposed to unfiltered and unsparingly sterilizing solar ultraviolet rays and cosmic radiation. It would seem that the only vestige of our once confident expectation of life to which we could cling was the possibility of finding fossil evidence of past organic activity of a very lowly kind. The ambitious experiments of our two Viking lander probes, however, soon relegated these hopes, too, to the realm of romantic daydreams.
Yet in the nearly 20 years since, some have not given up hope of finding that life did indeed get off to doomed start in that first billion year window of opportunity, before the consequences of geological facts gained the ascendancy. Now, it seems, their faith has been rewarded.
Not that long ago, the assertion that we might already have samples of Martian rock on Earth, catapulted here by some unknown asteroid impact on Mars, would have been greeted by contemptuous laughter. But the evidence from trapped gasses within a small number of meteorites has been convincing. A small number of meteorites have gas inclusions with the same chemical makeup and abundances that our probes have found on Mars. Now, it seems, at least one of these Martian rocks harbors something much more amazing - fossil evidence of ancient bacterial microbes, even of their feces. The news was not announced immediately. Recheck after recheck was made and alternative hypotheses tested. While other scientists are reserved, wanting to test the samples for themselves, a conservative NASA seems convinced that the evidence is strong enough for an announcement: Mars once harbored life!
As exciting as the finding is, it is important to keep it in perspective. All we have found are traces of bacteria-like creatures. And it could well be that life on Mars never advanced beyond this humble beginning. In fact on Earth, it would be another two billion years before the manifold possibilities of the monocellular plan long explored, multi-cellular "metazoan" life would make its appearance. To most of us, this is what we mean by life: plants and animals of a size and scale to which we can relate - living creatures we can see with the naked eye. Despite the new finding, Mars may never have supported life that most of us could appreciate.
That is not the final word. On Earth, microscopic one-celled creatures often form clearly visible colonial associations - mats of floating algae, for example - and it is not inconceivable that someday investigators on Mars will find fossil relics of such things; unlikely, perhaps, but not impossible.
As for living specimens, it is more probable that no life, even microbial, still ekes out an existence in today's Mars. This particular cradle of life, it would seem, is now empty. To find otherwise would be equally momentous news, and there remain true believers confident it will turn out so.
The real story, however, lies in the implication that where life can begin, it will begin, much as where iron can rust, it will. Nature, it has long been said, never does anything once. In this heroic but stillborn instance of emergent life within inspection distance of our home planet, we find encouraging support for the belief that the universe must be full of life-bearing planets around other suns. It seems reasonable that in the majority of such cases, life will get off to a doomed start, a ceiling to its ambitions placed upon it by geological if not celestial facts. But if life is indeed a natural development under the right conditions, then it must be common enough that here and there it has flowered in staccato asteroid-impact-punctuated fashion, for eons, as it has on our native Earth.
That we, as sentient beings, are not alone is still a tenet of faith. But that Earth, as a cradle of life, is not alone, now seems a warranted conclusion of empiric evidence. This news, if as we expect it is supported in years to come by a flood of new evidence gathered on Mars itself, will mark a watershed in human intellectual and scientific history. We have all reason to be cheered.
Undoubtedly, this latest scientific find is destined to become a watershed event in the history of human expansion into space. Probes budgeted for Mars, but yet to be built, may have their currently manifested instruments adjusted or optimized to shed direct or indirect light on this discovery, hopefully to uncover supporting evidence. New probes will be designed from scratch and targeted to promising sites on Mars. And there will be powerful new motivation behind existing plans for a "Mars Sample Return" mission, motivation to pull it off sooner and to return a more ambitious sample booty.
But always in the background from now on will be the lure of a human expedition to Mars, a "mission with a mission," a mission even politicians may find hard to resist. Is that something space activists ought to have mixed feelings about? After all, its presumed primary goal would be paleontological exploration with geological and mineralogical exploration, secondary and tertiary drivers. Establishment of a first Martian settlement would NOT be a logical outcome. If it came, it would be driven by economic rationales unrelated to the life question, but perhaps on mineralogical assets found serendipitously during the exploratory mission.
Indeed any exploratory mission searching for fossil evidence of life is likely to be a unique undertaking not to be repeated. No matter what its outcome, no matter how much scientific curiosity remains - it would be par for the course for any answers to raise further questions - the public's curiosity and the consequent political itch will have been satisfied. Any series of missions planned from the outset, targeted to sites with different promises as in Apollo, is likely to be cut short out of public, media, and political boredom.
In the end, sustained exploration has to follow settlement, not precede it. It has always been so, certainly in the Americas and in Australia. As we have said before, and as Jeff Liss has also pointed out, the economic rationale for development of Mars is a case that has yet to be made. [In the July/August issue of Ad Astra, "The Case For Colonizing Mars" pp. 36-38, Bob Zubrin makes an important start!]
Where does this leave us? In our opinion, the siren call implicit in the Meteorite From Mars should not be resisted. Let the government(s) do this. Exploration is a proper government function!
But what about the Moon? While there is more exploration needing to be done on Earth's eighth continent, not a great deal more needs to be done prior to the establishment of a beachhead settlement designed for economic development of the Moon's considerable assets and advantages. And such activity, supporting infrastructure aside, is not a function best done by government, but by free associations of people seeking their own economic betterment. We do not need the government to "do the Moon"; we must not wait for the government to "do the Moon"; we stand only to get a half-assed bungled-up job if the government does the Moon.
So here is "the fork in the road." Let governments proceed with Mars exploration. We tag along to ferret out the rationales for follow-on settlement. Meanwhile, governments will be paying for infrastructure needed to support manned Mars expeditions, infrastructure that will then be available for commercial concerns aiming at the Moon, infrastructure that otherwise might well never be built. Let enterprise then set up shop on the Moon. To each sector, what it does best. PK (Peter Kokh)
With the spectacular "Centennial" Olympics in Atlanta still fresh in our minds, we take time out to speculate about the possible expansion of "The Games" into space and its many venues so diversely different from all that's familiar on Earth. What shape will Olympic sports, gymnastics, and track and field events take? See the article that follows.
Contents of this issue of Moon Miners' Manifesto