Posted on 07/30/2018 3:44:07 PM PDT by LibWhacker
Science fiction writers have long featured terraforming, the process of creating an Earth-like or habitable environment on another planet, in their stories. Scientists themselves have proposed terraforming to enable the long-term colonization of Mars. A solution common to both groups is to release carbon dioxide gas trapped in the Martian surface to thicken the atmosphere and act as a blanket to warm the planet.
However, Mars does not retain enough carbon dioxide that could practically be put back into the atmosphere to warm Mars, according to a new NASA-sponsored study. Transforming the inhospitable Martian environment into a place astronauts could explore without life support is not possible without technology well beyond today’s capabilities.
Although the current Martian atmosphere itself consists mostly of carbon dioxide, it is far too thin and cold to support liquid water, an essential ingredient for life. On Mars, the pressure of the atmosphere is less than one percent of the pressure of Earth’s atmosphere. Any liquid water on the surface would very quickly evaporate or freeze.
Proponents of terraforming Mars propose releasing gases from a variety of sources on the Red Planet to thicken the atmosphere and increase the temperature to the point where liquid water is stable on the surface. These gases are called “greenhouse gases” for their ability to trap heat and warm the climate.
“Carbon dioxide (CO2) and water vapor (H2O) are the only greenhouse gases that are likely to be present on Mars in sufficient abundance to provide any significant greenhouse warming,” said Bruce Jakosky of the University of Colorado, Boulder, lead author of the study appearing in Nature Astronomy July 30.
Although studies investigating the possibility of terraforming Mars have been made before, the new result takes advantage of about 20 years of additional spacecraft observations of Mars. “These data have provided substantial new information on the history of easily vaporized (volatile) materials like CO2 and H2O on the planet, the abundance of volatiles locked up on and below the surface, and the loss of gas from the atmosphere to space,” said co-author Christopher Edwards of Northern Arizona University, Flagstaff, Arizona.
The researchers analyzed the abundance of carbon-bearing minerals and the occurrence of CO2 in polar ice using data from NASA’s Mars Reconnaissance Orbiter and Mars Odyssey spacecraft, and used data on the loss of the Martian atmosphere to space by NASA’s MAVEN (Mars Atmosphere and Volatile Evolution) spacecraft.
“Our results suggest that there is not enough CO2 remaining on Mars to provide significant greenhouse warming were the gas to be put into the atmosphere; in addition, most of the CO2 gas is not accessible and could not be readily mobilized. As a result, terraforming Mars is not possible using present-day technology,” said Jakosky.
Although Mars has significant quantities of water ice that could be used to create water vapor, previous analyses show that water cannot provide significant warming by itself; temperatures do not allow enough water to persist as vapor without first having significant warming by CO2, according to the team. Also, while other gases such as the introduction of chloroflorocarbons or other fluorine-based compounds have been proposed to raise the atmospheric temperature, these gases are short-lived and would require large-scale manufacturing processes, so they were not considered in the current study.
The atmospheric pressure on Mars is around 0.6 percent of Earth’s. With Mars being further away from the Sun, researchers estimate a CO2 pressure similar to Earth’s total atmospheric pressure is needed to raise temperatures enough to allow for stable liquid water. The most accessible source is CO2 in the polar ice caps; it could be vaporized by spreading dust on it to absorb more solar radiation or by using explosives. However, vaporizing the ice caps would only contribute enough CO2 to double the Martian pressure to 1.2 percent of Earth’s, according to the new analysis.
Another source is CO2 attached to dust particles in Martian soil, which could be heated to release the gas. The researchers estimate that heating the soil could provide up to 4 percent of the needed pressure. A third source is carbon locked in mineral deposits. Using the recent NASA spacecraft observations of mineral deposits, the team estimates the most plausible amount will yield less than 5 percent of the required pressure, depending on how extensive deposits buried close to the surface may be. Just using the deposits near the surface would require extensive strip mining, and going after all the CO2 attached to dust particles would require strip mining the entire planet to a depth of around 100 yards. Even CO2 trapped in water-ice molecule structures, should such “clathrates” exist on Mars, would likely contribute less than 5 percent of the required pressure, according to the team.
Carbon-bearing minerals buried deep in the Martian crust might hold enough CO2 to reach the required pressure, but the extent of these deep deposits is unknown, not evidenced by orbital data, and recovering them with current technology is extremely energy intensive, requiring temperatures above 300 degrees Celsius (over 572 degrees Fahrenheit). Shallow carbon-bearing minerals are not sufficiently abundant to contribute significantly to greenhouse warming, and also require the same intense processing.
Although the surface of Mars is inhospitable to known forms of life today, features that resemble dry riverbeds and mineral deposits that only form in the presence of liquid water provide evidence that, in the distant past, the Martian climate supported liquid water at the surface. But solar radiation and solar wind can remove both water vapor and CO2 from the Martian atmosphere. Both MAVEN and the European Space Agency’s Mars Express missions indicate that the majority of Mars’ ancient, potentially habitable atmosphere has been lost to space, stripped away by solar wind and radiation. Of course, once this happens, that water and CO2 are gone forever. Even if this loss were prevented somehow, allowing the atmosphere to build up slowly from outgassing by geologic activity, current outgassing is extremely low; it would take about 10 million years just to double Mars’ current atmosphere, according to the team.
Another idea is to import volatiles by redirecting comets and asteroids to hit Mars. However, the team’s calculations reveal that many thousands would be required; again, not very practical.
Taken together, the results indicate that terraforming Mars cannot be done with currently available technology. Any such efforts have to be very far into the future.
This research was supported in part by NASA through the MAVEN and Mars Odyssey THEMIS (Thermal Emission Imaging System) projects.
Bill Steigerwald / Nancy Jones
NASA Goddard Space Flight Center, Greenbelt, Maryland
301-286-8955 / 301-286-0039
william.a.steigerwald@nasa.gov / nancy.n.jones@nasa.gov
Master Image Caption: This is an artist's model of an early Mars — billions of years ago — which may have had oceans and a thicker atmosphere. It was created by filling Mars' lower altitudes with water and adding cloud cover. The locations for the ancient ocean are based on current altitudes and do not reflect the actual ancient topography. It can be downloaded here: https://svs.gsfc.nasa.gov/13016
Credit: NASA/MAVEN/Lunar and Planetary Institute
We have the technology, but it wouldn't involve cranking up the CO2 level, that's just global warming hoaxter idiocy. We could mine frozen nitrogen and oxygen in the outer solar system, and deliver it in chunks just big enough to amount to something but not so big that we couldn't move it and steer it.
But it would take a lonnnng time, and a lot of cash..
Q: How much energy would it take to generate a magnetic field sufficient to protect Mars’ atmosphere?
Given that, the best bet might be to move one of the moons thought to have much more water than Earth, preferably in the form of ice, to Mars orbit. (Not TOO close - you don’t want big problems from tidal effects.) Set up a gigantic catapult and start chucking ice down to Mars, using the heat of entry (it’s not really RE-entry) and likely detonation to vaporize the ice.
Obviously this takes tech and energy expenditures we can only dream about at present... It might make more sense to use Mars as one source of material to build a Ringworld.
For later.
L
Along with the "In the future it is quite possible..." caveat we will still need to get help from the Vulcans to create additional planetary gravity on Mars strong enough to retain an atmosphere.
Don't hold your breath.... so to speak.
Oh, and the added gravity will also cause a stronger tidal force that will cause Phobos to tear itself apart and crash onto Mars sooner than expected. Splat.
Or a couple of kids and skateboards.
I sure would like to live long enough to at least see earth colonies living on Moon and Mars
The calculations indicated that a 1-2 Tesla (10,000 - 20,000 Gauss) magnetic field generator positioned at the gravitationally stable L1 Lagrange Point between the Sun and Mars, would provide enough protection for gases to accumulate in the atmosphere over time, and provide immediate reduction of radiation on the surface of Mars. They do no say how long it would take, or how difficult it is to generate such fields.
Uh, no. Mars' gravity is strong enough to hold onto a decent atmosphere by itself, if that atmosphere can be protected from the solar wind. That's the whole idea.
No Vulcans. Phobos stays put. Mars gains an atmosphere and terraforming proceeds as planned. Carl moves to Mars.
The combination of the plentiful basic material, and only 38% as much gravity to boost it from, makes Mars an attractive source for steel to build space stations ...and a mighty interstellar fleet.
Interesting - I had not seen your link, until just now, but that sort of protection is exactly what I was thinking of.
Now, that said, the article at the link refers to 1 - 2 Tesla, or 10,000 to 20,000 Gauss. Where? At the surface of the “inflatable generator”? 10 kGauss is a STRONG field —much stronger flux density than you’d see at the surface of a conventional ceramic magnet, for example, and I challenge anybody to pull apart by hand (in the direction of magnetization) a couple of 6” diameter ceramic ring magnets (like those found in a medium price guitar speaker.)
For another comparison, Earth’s magnetic field at the surface ranges from 0.25 - 0.65 Gauss.
With current and near-term technology, human habitation of Mars will be mostly underground. Far cheaper and better protection against solar radiation, wind, and the cold. Setting aside insulation and shielding, more expensive in the short term than surface structures, but probably cheaper total cost of occupancy given the attrition on surface structures vs. the permanence of things carved out rock especially on a seismically-inert planet.
“Where?”
In the article, they propose putting the magnetic shield generator in space. About 675,000 miles off Mars (320 radius lengths), in a gravitationally stable balance point (Lagrange Point L1) in Mars’ orbit around the Sun.
There it could passively sit of it’s own (lack) of weight, without fuel demands to maintain orbit (only orientation - and to produce the huge magnetic field).
The articles that claim a breathable atmosphere can be sustained on Mars depend on a lot of handwaving.... for a long time. And none I’ve read talk about where the nitrogen component will come from, if the atmosphere is not to be essentially O2 plus CO2.
A really-really deep pit mine could collect the remaining atmosphere. Larry Niven would probably chuckle-Canyon.
Current loop planet sized. Dream big.
Would be under pressure load from solar wind, need to accelerate diverted solar plasma for counter-thrust to hold position.
There is nothing insufficient about Mars' mass (size is irrelevant). Early Mars had a LOT of carbon dioxide. The weight of that gas alone was enough to provide Mars with an atmospheric pressure equal to that on today's Earth. Even Saturn's moon Titan has a substantial atmosphere (Titan is under the protection of Saturn's magnetosphere). The problem is, if you let the solar wind get to your atmosphere, you're going to lose it. Even Earth will lose its atmosphere it our molten core quits spinning.
Yep, they mention that.
Plus, it’s going to need regular servicing and it’s way out in the middle of nowhere. Better than nothing though.
Actually, not a bad idea.
Thank you for reinforcing my argument that any flights of fancy regarding a manned mission to Mars should be set aside until we can overcome the physics restricting us to chemical-based escape from Earth’s gravity.
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