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Listen, I'm getting that. You want to go to Mars. I want to go to Mars. (Sort of.) And the plan, it's good. A rocket with people. A base on the moon. Then more rockets and more people. Start making fuel on the surface, maybe drop it along the way. An outpost becomes a base becomes a domed city. And then: terraforming.
Revive Mars, build a new atmosphere with what's left in its soil – frozen carbon dioxide, most likely – to increase atmospheric pressure, depend on greenhouse warming (you know, like the climate change?) to make the place warm enough so that the frozen water, buried underground, melts and comes back roaring. Oceans! Air! Maybe breathable, but at least enough so that you do not have to walk in a spacesuit. Boom (where the value of "boom" = 10,000 years, plus or minus). At the top of gravity we go, and we can advance on the Earther-Martian Colony Revolution all that hard science fiction promises.
They are not crazy. Astronomer Carl Sagan, a symbol of scientific rectitude, pioneered "planetary engineering" in 1971, melting the water vapor from the polar ice of Mars to create "much more lenient conditions." Twenty years later, astrobiologist Christopher McKay suggested that terraforming Mars was possible as long as the planet still had enough carbon dioxide, water, and nitrogen to volatilize and pump into l & # 39; atmosphere.
But some scientists who are studying Mars are trying to explode that … sealed bubble, recirculating with oxygen, protected against radiation. If a new badysis is correct, conditions on Mars prevent existing technology from turning it into a garden of Earth's delights.
"We managed to collect for the first time a reasonably clean inventory of the CO 2 on Mars," says Bruce Jakosky, a global scientist at the University of Colorado and co-author, with Christopher Edwards of Northern Arizona University, the new document "Most of it was lost in space, a small amount of polar ice and shallow carbonaceous minerals, and an unknown amount of deep carbonates." adding pieces of CO 2 stuck on "adsorbed" rocks "On their surfaces – and a little more locked in water – the molecular cages called clathrates do not help. "Even if you put it all in the atmosphere, it's not enough to warm the planet," says Jakosky.
The atmospheric pressure at the surface of the Earth is about 1 bar; it takes about as much CO 2 on Mars to bring the surface temperature to freeze; Even 250 millibars alone would change the climate significantly. And Mars had this and more – geology and surface morphology strongly suggest the existence of liquid water on the surface of the planet in its distant past, which means that it has to be hot enough and pressurized enough to retain this liquid water. If the planet had CO in the same proportions of Earth and Venus, says Jakosky, we would expect the equivalent of 20 bars of the substance to be somewhere mineralized in carbonate, frozen in ice polar. "For the last 40 years, the science mantra of Mars has been looking for carbonate deposits that must exist, because CO 2 was supposed to be somewhere," he says. "In the crust, it might be accessible.If it has reached the top and is lost in the atmosphere, it is gone."
New radar data provided new numbers for the CO 2 near the polar caps. The Mars Reconnaissance Orbiter has collected numbers for the carbonate distribution. And the Mars Atmosphere and Volatile Evolution (Maven) probe, in orbit since 2014, quantified the gas lost in space. (Jakosky is the principal investigator for this mission.) And the results are ugly, if you are an alleged terraformer.
The polar caps give you about 15 mbar. The strip-mining of the carbonates gives you less than 15 mbar; maybe up to 150 mbar if you really press. Gas adsorbed in the regolith? Just 40 mbar even if you treat all the dirt on Mars to a depth of 100 meters. "It would be almost impossible to climb above 40 or 50 millibars, and it's not enough pressure, and not enough of an effect on the temperature," Jakosky says. "You could probably increase it by a factor of two or three, but even that does not bring you closer to the amount required to produce significant warming."
Sigh.
Or … well, maybe he's wrong. The Terraforming pioneer, Christopher McKay, still has hope. "The key question for terraforming is the amount of CO 2 N 2 and H 2 O on Mars Unfortunately, there is nothing again here to solve this question, "write McKay. Jakosky's Maven results only show that the ex-carbon dioxide of Mars is gone, not all. So maybe it's still there, says McKay. "We are still very uncertain about the amount of CO 2 under the surface, we do not have good data and we have to drill deeply to get it."
is true that Mars remains full of surprises – as last week's announcement of a possible sea of brackish liquid water under the poles. So, these newly crunched numbers do not dampen the minds of real Mars jockeys. Robert Zubrin, president of the Mars Society and author of The Case for Mars says that Jakosky's figures are "systematically pessimistic". Zubrin does not need a full bar. Give it just 300 mbar. This is, like, the pressure of Mount Everest. "Two hundred millibars means no suits, which means you can create dome-shaped speakers where the pressure inside is equal to the pressure on the outside," explains Zubrin
Zubrin et al. McKay point out that stretching the boundaries of the hypothesis gives a little more relief.red planet.The artificial greenhouse gases – maybe chlorofluorocarbons made from abundant chlorine in the Martian regolith, or something even more exotic and working faster, a "super greenhouse gas", could do the job.If anyone knew how to make them.And release them.And make sure that they have not destroyed the little ozone that exists, so that the ultraviolet radiation does not join the cosmic radiation killing the planet Mars without magnetosphere
(Related: If you believe that It is possible to terraform Mars, you must also cro ire to climate change caused by man, because it is the same process: even if it is impossible to terraform Mars, it is clearly possible to aeoform the mid-latitudes of the Earth because people do it.) [1965-19003] The water on Mars makes it a little more likely that something is already alive there. "Terraforming" a world with native life is the difference between the Genesis effect and the Genesis torpedo, it's an ethical conversation that has to happen with the scientific and political.)
Which raises a question triply Linked: Why? "We are moving away from science here, but I would question the reason for being terraforming," Jakosky says. "Having a backup planet in case we screw this one, or it's bading external drivers, I think is a mediocre argument.It's a lot easier to keep this one nice and with a mild climate than to change the environment of Mars. "
Explore? Sure. Permanent scientific base? Absolutely. But the cities? Oceans? Cbads? Take a deep breath because, as far as we know, you can literally do nothing else in the universe.
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