#93 March 1996
Section 18.104.22.168.093.of the Artemis Data Book
In the previous "Mars Theme" issue, MMM # 83 MAR '95, on pp. 7-8 "Searching for OLD LIFE on Mars" (P. Kokh), we broke the topic down into two separate questions:
We concluded with a discussion of the implications for Martian settlement dreams, pointing out that the Romanti-cists who hope against hope that we will find some primitive (at least!) life forms still extant life on Mars, had better hope that they are wrong. It is incomprehensibly naive to think that should we find life on Mars of any sort, that the political / rabbleocracy powers-that-be would allow humans (us!) to settle there. The Fourth Planet would forthwith be declared a quaran-tined biological preserve for the rest of time. "Humans and all Earth Life keep out!" We could hardly disagree more with the sentiments expressed by editor Jeff Liss in the recent issue of Inside NSS. He had called "disappointing" the recent finding that the Viking "No-Life-On-Mars" experiment results were not flawed after all.
If all we find are fossil relics and perhaps a few incomplete strands of DNA (we should rejoice at finding that much!) Jurassic Park type reconstructions of native life form populations are most unlikely.
If an eco-system does survive, we could not hope to see any significant further evolution (beyond anecdotal differen-tational radiation of surviving species into new niches in a restored or rejuvenated more benign climate) within the lifetime of humanity, even if it be a million years - and not even if we succeeded in restoring, permanently, the former more life-accommodating climate with a stabilized all-Martian biosphere and biota. Romantic ideas to the contrary should not be entertained. We would be left with only pre-metazoan life, one-celled plants and animals - nothing we could see with the naked eye! So rather rejoice that Mars is empty of life!
That is not the end of the story. That Mars has no life, and quite possibly never spawned life even in earlier wetter and warmer times does not make the planet "barren". It only makes the planet "virginal". That conditions may have never been special to allow life to rise on its own, does not mean that life, originated elsewhere, and then bioengineered to fit Martian conditions, could not be successfully transplanted to Martian soil, with intelligent guidance, corrections, and compensations. That is a tall challenge, however, but we hope to sketch how it might be accomplished. Or at least, the first steps one intending to green the planet might take.
The biological side of Greening Mars would have to be brought about "pari passu" i.e. step by step together with the geological rejuvenescence of the planet. Rather than "terraforming" Mars by making it a copy of Earth, rejuvenais-sance looks not at Earth, but the early Mars itself, for its standard of achievement. The planet does need to be warmed, first to the point where a third of the atmosphere no longer freezes out over the poles each winter (twice a Martian year, during northern and southern winters, i.e. paradoxically during southern and northern summers, i.e. atmospheric pressure is at its height only during spring alias fall). Warming it still further will free up additional carbon dioxide bound up at the poles or in permafrost year around. Both temperature and pressure have to be increased to the point that liquid water can exist in the open, even if only as seasonal dews.
But in this article, we want to look at the biological part of the equation. Obviously we want to, have to, use genetic material from sundry terrestrial plants (possibly animals too) and arrive at species hardy enough to survive and breed on a rejuvenated Mars.
What we have to start with is, species after species, a long ways from being remotely Mars-hardy. The harshest most demanding habitats on Earth are all much friendlier than the friendliest place on Mars, even possibly on the wetter, warmer Mars of yestereon. Where do we start? How do we proceed?
The most severe habitats on Earth are the deserts, the Andean altiplano of Peru and Bolivia, the tundra of northern Alaska, Canada, Greenland, Scandinavia, and Russia-Siberia, and the Antarctic islands, shores, and "dry valleys." No trees grow in these areas, not even the stunted, wind-grotesqued caricatures we find at the tree line on mountain slopes and at the tundra limits. Animals fare better, thriving on seafood, other animals and very lowly plants.
Animals, however, need an oxygen-rich atmosphere, which we don't have, have never had, on Mars. Plants, in contrast, thrive on carbon dioxide - it has been shown that most plants can be grown successfully in an artificial atmosphere of reduced pressure (e.g. 1/10th normal) of just carbon dioxide, the major component of Mars air. That is to say, that plants and crops can be grown on Mars in greenhouses pressurized with warmed Martian atmosphere, simply compressed tenfold - nothing else added, besides water, of course. That we could gradually lower temperature and pressure to meet the improving Mars climate halfway with bioengineered species that could be planted outdoors either to be tended and cultivated or left to grow wild is the general idea.
We call this redhousing, rather than greenhousing. We are using the air of the red planet Mars and an improved but still Martian climate - not the air of Earth and an idealized terrestrial climate. This is not to say we shouldn't have traditional greenhouses on Mars. We do have to eat and clothe ourselves and provide for pharmaceuticals and other needs, day in and day out - while we are busy in the redhouses preparing to mate a rejuvenated red planet with a blanket of life bred and engineered to go native there.
Will there someday be forests on Mars, with real trees even if they look unearthly. That's a possibility beyond our vision. Our starting point will likely be the lichen, a moss-like plant that is basically a fungus able to survive thanks to a symbiotic relationship with green algae. That this feat is cooperative is discouraging, that we have to start with a very specialized complex - compound creature. The best place to start in any plan to evolve a radiant family of diverse species is with something very generalized, able to survive in a wide range of habitats. But thankfully, we have many species of lichens in the northern hemisphere and a few in the southern.
But are lichens the only starting point? Not necessarily. Many plants handle annual freezing in stride, but the much longer, much deeper freezes of Mars would likely be to much for them. Witness the tree line!
Some antarctic organisms in the animal kingdom, come equipped with an intra-cellular antifreeze - glycol. But plant cells have protoplasm as well. If the gene responsible for the ability to produce glycol can be transferred successfully to some plants, that might give us additional breeding stock for Mars. The more starting points, the more diverse the ultimate possibilities, the more niches on Mars that can be greened.
But hard long freezes are not the only challenges Mars poses. Severe desication is another. Desert plants, like cacti and other "succulents" withstand prolonged very arid stretches well. On Mars the dessicating capacity of the cold parched winds is extremely intense. What the cacti and other desert plants have to offer, will not be enough. But it is a start. Nor is there any reason why the glycol gene cannot be added to the genetic consist of desication-hardy plants, and vice versa. Chile's Atacama, California's Death Valley, NW China's Takla Maklan are among the most challenging niches for desert life.
And then there is the untempered ultraviolet of the more distant, cooler, Martian "Sun". Mars tenuous atmosphere without free oxygen (O2) or ozone (O3) is transparent to this tissue-killing radiation. Here on Earth, the most UV-resistant species are those that live at very high altitudes. The nearer to the equator, the higher up the maintain slopes does life thrive. Plants growing wild in various niches of the Peruvian-Bolivian altiplano (high altitude 13,000-15,000 ft. intermountain basin-plateau between the Western and Eastern Cordillera) may yield genetic contributors to this resistance. - a third ingredient.
We must add one more characteristic. On Earth many plants are pollinated by insects and birds. Bioengineering animals to breath a carbon dioxide atmosphere seems science-fantastic, not merely science-fictional. So we may want to end up with plants that are wind-pollinated or use some other assist than the help of sweet air breathing animal species.
The list of favorable attributes doesn't end here. We could select also for abrasion resistance to wind-borne dust, low reproductive rates, interruptable life cycles, etc.
What plant forms will be most receptive to such diverse genetic additions? Your guess is as good as mine. It is not impossible that the best Mars-hardy hybrids will have as ancestors plants that boast none of the assets mentioned, but will have proven receptive to all of them.
Nor do we have to wait until we are on Mars to begin the experimenting. There are so many candidate plants to start with, so many recombinant genetic combinations to be tried. The sooner we begin, and the more the facilities we set up, the sooner are we likely to have our optimism and enthusiasm rewarded - or discouraged.
|On Mars, as we pointed out, all we will need is a shelter that holds compressed, warmed Martian air.|
|On Earth it will be a little trickier. Unbuffered, the facility would be subject to inexorable leaks from the higher pressure, vastly more oxygen-sweet air of the host planet:|
|One way we can buffer the facility and prevent hasty degradation of the special atmosphere within, is to use a surround chamber with either Earth air or Mars air at relatively low pressure. Air would tend to leak out of the red house chamber, preserving quality, with makeup quantities from special tanks. If pressure in the surround got to high (too close in value to that of the inner chamber) the excess could be pump- exhausted to the outside terrestrial atmosphere.|
|Or the redhouse could be covered and buffered by water in a host lake or pool or tank. This would also tend to prevent atmospheric contamination. A wet porch could not be used for entry, however, as oxygen dissolved in the water would outgas into the carbon dioxide atmosphere within, polluting it.|
The strategy is one of convergence, breeding ever more cold, drought, and UV hardy species for ever more Mars-like conditions in Mars redhouses Meanwhile, outside the actual Mars climate is improved by human activity and inter-vention. In fact, the degree to which these experiments are successful, will co-determine the goals set for rejuvenescence of the planet. Like politics, the greening of Mars will unfold as the art of the possible. As politics should be (but isn't) it will also be the art of co-promise, not compromise - what can be achieved in improving the climate, temperature, pressure, and wetness of the planet - and what can be achieved by recom-binant DNA biological engineering and breeding for Mars-hardiness. We can only speculate at the results.
On Earth, and most likely on all life-bearing planets, evolution has not been smoothed. Each outburst of new species origination slows into a self-stabilizing rut, impeding further progress. It is the periodic decimation of existing species by comet and asteroid impacts that has cleared the way for new evolutionary growth. The future of redhousing will include man-made catastrophes to severely purge prematurely stabilizing indoor ecosystems and clear the way for new rounds of the game of survival of the most (man-determined) fittest.
As progress allows us to preview the eventual results, we will know better what areas of Mars to set aside as future areozoic parks and preserves. Low-elevation basins and canyons will have the highest atmospheric pressure, the warmest temperatures (latitude for latitude) and be the first to experience dews and eventually free standing and/or flowing open water. The Mars Orbital Laser Altimeter aboard the Mars Global Surveyor (November '96 launch, September '97 arrival) will give us a good idea of where these oases-to-be are located. We will then even be able to speculate about setting aside right-of-ways for future parkways.
To return to the point we made at the outset, if Mars is devoid of life, that makes is a virgin world, not a barren one. The cosmic vocation of humanity, unsuspected by all the world's pretentious scriptural traditions, may indeed be to bring life to places where it can survive, but never originate on its own. Only an intelligent species can serve this function. Humanity then becomes "the" reproductive organ of Gaia (meant as the name of Earth-Life in aggregate, not as some mythic meta-individual).
Further, through interstellar flight, even if it only be of ships bearing nothing more than seeds, spores, and fertilized eggs, this particular human vocation takes on a more general Cosmic significance, in the Solar neighborhood (probe-reachable limits to be determined!) beyond this nursery womb-world nano-turf we call Earth.
Contents of this issue of Moon Miners' Manifesto