|
|
          |
TERRA-FORMING MARS
Ancient astronomers, noting the bloody colour of a certain bright planet, named it Mars, after their god of war. Their intuition was right - Mars is indeed a unforgiving place.
But this wasn't always the case. Photographs of dry river beds, taken from orbital spacecraft, show that Mars was once warmer and wetter than it is now. And like Earth, Mars has frozen ice-caps at both poles.
The recent discovery of a Martian meteorite in Antarctica lent substance to this idea. This inconspicuous rock contained mineral residues consistent with bacteriological activity.
"My personal opinion is that there probably is life on Mars", continues Gordon. "There is probably life on millions of planets and other solar systems, but if we find life on Mars that evolved seperately from life on Earth, that really strengthens the argument that there is a lot of life out there and that we are not alone". If Mars supported life once, then perhaps it can again. The first step would be to establish a human colony. But would the Roman god of war tolerate a motley band of human intruders?
At it's closest point to Earth, Mars is only 60 million kilometres away. Using present day propulsion systems, it takes 6 months to get there, which is a stone's throw in the cosmic scheme. In our search for a second foothold on the mountain of space, Mars is the logical step.
Until now, the assumption has been that we would require a giant space-ship to heft huge amounts of fuel and food across the inky depths of space. And since it would be impossible to launch such a craft from Earth, we would need an orbiting space-station to build it. This was one of the early justifications for building the International Space Station. According Robert Zubrin, author of "The Case for Mars", this is not necessary. Zubrin has hatched a plan called "Mars Direct", that describes how astronauts can travel light and build when they get there.
"The idea is", continues Gordon, " to send a series of unmanned missions, one every two years, to do scientific exploration of Mars and also to put some of these new technologies on Mars and test them there in an unmanned way. There is an instrument being sent to Mars in 2001, that will be extracting oxygen from the Martian atmosphere. The idea is to be able to extract the oxygen from the Martian atmosphere and collect it and basically build up a store of rocket fuel, which you can use to come back from Mars. You would manufacture the fuel on Mars to get back to Earth". In the longer term, the Mars Direct plan envisages a permanently occupied human settlement. Once again, a "living off the land approach" is seen the key to cost-effective Martian exploration.
In a certain sense, evolution here on Earth has performed precisely that function. Four Billion years ago, the Earth was as desolate as Mars is now. Terra-forming requires that human beings become the agents of this process. Terra-forming would most likely begin with attempts to raise sub zero temperatures and thicken the atmosphere. One option is to build factories on Mars that produce greenhouse gases. CFC's are being phased out on Earth because they contribute to global warming, but ironically this is exactly what will make them indispensable on Mars. By manufacturing specific halocarbon gases, the plan is to build up an ultraviolet shield and ozone layer that will insulate and protect the surface of the planet. As the temperature rises, frozen carbon dioxide trapped at the poles will evaporate. The atmosphere will become thicker, trapping more of the sun's heat. With more heat, more carbon dioxide will evaporate. It's a circular process that scientists call positive feedback. Once the temperature rises, water will start to flow freely on the Martian surface, meeting the major requirement for life. To speed it up the process, Zubrin suggests using large orbiting mirrors to reflect sunlight directly on the polar caps, vaporizing CO2 and melting the ice. In other words, Mars will be terra-formed using smoke and mirrors. The final step would be to introduce genetically engineered bacteria and plants to release oxygen from carbon dioxide by photosynthesis. According to Zubrin, the whole process could take as little as 900 years. Which raises the question: why bother to terra-form Mars? What can we get out of it? "I would really think twice", continues Gordon "about completely changing the character of a whole planet. Now , we may have to do that if there is some disaster that is causing impending end of life on earth, and in that case, I think it is justified. But just to do it for economic expansion, is sort of like cutting down the rain forests. Mars is Mars, love it for what it is". A habitable planet would certainly make it easier to mine there. Deuterium, currently valued at $10,000 per kilogram, is five times more common on Mars than on Earth. But to treat Mars as a resource would be to miss the point. Terra-forming Mars would reaffirm the pioneering spirit that took us to the moon and re-establish a common vision and sense of purpose as to our role in the cosmos. And if we can tame the surface of Mars then perhaps, with time, other forms of life will evolve, and with them, that most precious fruit of all: consciousness.
Contacts:
|
It's one-and-a-half times further from the sun than the Earth, so it's cold. At night the thermometer drops to - 90 C.
Consequently, there's no liquid water on the surface. Just arid, red dust.
Gordon McKay from the Johnson Space Centre at NASA explains, "Most people believe that the climate of Mars,
millions or billions of years ago was very different to the climate there now, and that it was much warmer and much wetter.
There were rivers and possibly even an ocean. Many people, myself included, feel that under those conditions, it is very
likely that life would have developed on Mars".
The implications are enormous. If life once existed on Mars then you can bet your bottom dollar that it exists elsewhere in
the universe. In fact, the skies are probably teeming with it. That possibility, according to some scientists, is reason enough
to go there.
In fact, the closer one looks at Mars, the less unfriendly it becomes. It's the most earthlike planet in our solar system. It
rotates on a similar axis and experiences a similar seasonal cycle. The Martian day is 24 hours and 37 minutes.
But once we got there, what would we eat and how would we breathe? And how would we get back?
Mars contains all the elements necessary to support life - water frozen into the topsoil or lapping on the shores of underground
caves, carbon, nitrogen, hydrogen, oxygen. Everything necessary to sustain a small human habitat. NASA already has plans for 6
unmanned missions to Mars over the next 10 years in preparation for the first human mission.
But beyond establishing a human settlement on Mars, there is a further, even more fantastic goal - to transform the Martian
environment so that it can support life. In other words, to terra-form it.
