Martian Chronicles

GWYNNE DYER

June 02, 1993|By GWYNNE DYER

London. -- A generation ago, Ray Bradbury's ''Martian Chronicles'' was the first science-fiction novel to move beyond robust tales of interplanetary imperialism. His bittersweet vision of the human colonization of Mars had strong echoes of 1492 and the colonization of the Americas (one of the larger genocides of history).

Now the politically correct among us tend to regard human beings as a bipedal plague that must not spread any farther, and hardly anybody believes that there will be large numbers of people living anywhere but earth in the next century or two. But some people still dream the old dreams, and they are not all writers of science fiction.

Prominent among them are a group of scientists loosely called ''the Mars underground.'' They are led (to the extent that any of them will follow another's lead) by Christopher McKay of the U.S. National Aeronautics and Space Administration's Ames Research Centre in California, and they have a plan for ''terra-forming'' Mars.

That is, they have worked out a program for turning Mars into a second Earth. It will only take 280 years, provided we get started before 2015, and at the end of it all we will have a fresh, clean quite habitable planet to play with. Just what we are likely to need at that point.

As a place to live, Mars makes Antarctica look inviting. But the terra-formers have designed a plan, based on currently available (or at least easily imaginable) technology, that would transform the entire planet, with a land surface as large as Earth's, into an environment suitable for people.

Assuming that there is a permanent human base on Mars by around 2015 or 2020, the first job would be to raise the surface temperature to the point where life-forms more complex than lichens could survive. The favored way of doing that is to build giant chemical factories, probably powered by nuclear reactors, to pump trillions of tons of greenhouse gases into the thin, freezing atmosphere.

The chemicals needed are all present in the Martian crust, and after 50 years the extra solar heat trapped by the greenhouse gases would raise Martian surface temperatures enough that it would be time to move onto phase two: melting the polar caps. This trick would be accomplished by covering them with some dark substance -- perhaps genetically modified plants -- that absorbed the sun's heat instead of reflecting it back into space.

Melt all the water ice at the North Pole, and you have enough water to create shallow seas and lakes all over Mars. Melt the carbon dioxide cap at the South Pole, and you get a big bonus of extra greenhouse gas plus a large boost to atmospheric density.

At this point positive feedback takes over, and by 2100, say, the atmospheric pressure and average temperature would both have risen to the equivalent of conditions on Earth at an altitude of 18,000 feet. Now conditions are starting to resemble those on the Tibetan plateau -- except that the air contains almost no oxygen.

The final phase of the project would involve mining and heating immense quantities of iron oxides, abundant in the surface rocks of Mars, to liberate oxygen into the atmosphere. At the same time the vegetation typical of earth's tundra regions would be spread across the surface, to convert some of the atmosphere's carbon dioxide to oxygen.

By 2150 Mars' atmosphere would be thicker than the Earth's, and by 2200 the planet's surface would be green, not red. There would still not be enough oxygen for people and animals to breathe unaided, but even that might be achieved by running the atmosphere processors full blast for another century. So there you have it: a completely remade planet in no more time than it took to get from Christopher Columbus to the American Revolution.

Your first reaction, doubtless, is disbelief. It's over 20 years since we even bothered to send anybody to the Moon; the resources are simply not going to be made available for a project of this scale. Even if the engineering and the chemistry are sound, the energy demands of this project are probably higher than the Earth's entire present energy consumption.

But consider what the ''Mars underground'' is really designing here: a giant planet-wide system, complete with tens of thousands of atmosphere processors, tens of thousands of nuclear power stations, and Himalayas of mineral wastes, in order to transform and control an entire planet's environment.

It is a glimpse of the future, perhaps, but not necessarily the future of Mars. It is a vision of what our own planet's future may be like, a century or so from now, if our current activities destroy the natural balances of the terrestrial environment: atmosphere processing plants and the like not to change the Martian environment but just to maintain the Earth.

Independent British scientist James Lovelock said it best and first. If we continue down our present course, we will end up with the thankless, endless, incredibly costly job of ''planetary maintenance engineer'' to a global environment in which the natural control mechanisms have been overwhelmed by our activities. A lot less romantic than terra-forming Mars, but alas more likely.

Gwynne Dyer is a syndicated columnist.

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