Mars Terraforming Not Possible Using Present-Day

[wellis]

Well it looks like Mars won't be able to be terraformed. Not enough CO2 available.

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.

However, aerogel might be useful as a means to create greenhouses.

Raising crops on Mars is far easier in science fiction than it will be in real life: The Red Planet is an inhospitable world. Among other challenges, subzero temperatures mean water can persist on the surface only as ice, and the planet's atmosphere offers little protection to plants (or people) from the Sun's radiation.

Of course, NASA has plans to eventually put humans on Mars, using lessons it will learn from its Artemis lunar explorations. And those humans will need to eat. Being able to produce food on Mars would help reduce the quantity of supplies consuming valuable space and fuel on crewed missions to the Red Planet. But figuring out how - and where - to produce that food, while also being exceedingly careful not to contaminate Mars with Earth-borne bacteria, are some of the challenges scientists and engineers face.

In a new paper in Nature Astronomy, researchers propose that a material called aerogel might help humans one day build greenhouses and other habitats at Mars' mid-latitudes, where near-surface water ice has been identified. The study was funded by Harvard University's Faculty of Arts and Sciences.

Aerogel is a Styrofoam-like solid that is 99% air, making it extremely light. It's adept at preventing the transfer of heat as well, making it an excellent insulator; in fact, it's been used for that purpose on all of NASA's Mars rovers. Moreover, aerogel is translucent, allowing visible light to pass through while blocking ultraviolet light's harmful radiation. Most aerogel is made from silica, the same material found in glass.

In an experiment conducted by lead author Robin Wordsworth of Harvard, 2-3 centimeters of silica aerogel allowed light from a lamp tuned to simulate Martian sunlight to heat the surface beneath it by up to 150 degrees Fahrenheit (65 degrees Celsius) - enough to raise temperatures on the Martian surface and melt water ice.

 

[Timerover51]

The first thing is to determine how to live on Mars, even if in domed enclosures. Then worry about terraforming it.

 

[jcrocker]

The part I wanted to quote was

""As a result, terraforming Mars is not possible using present-day technology,” said Jakosky."

Once we get some people there, we can either MacGyver a work-around or start improving the technology.

Or import a few frozen carbon dioxide icebergs from a handy location.

Anyone remember the name of the Asimov story that had Mars settlers go get water ice from Saturn's rings? I'm going to see if I have that one.

 

[Timerover51]

The part I wanted to quote was

""As a result, terraforming Mars is not possible using present-day technology,” said Jakosky."

Once we get some people there, we can either MacGyver a work-around or start improving the technology.

Or import a few frozen carbon dioxide icebergs from a handy location.

Anyone remember the name of the Asimov story that had Mars settlers go get water ice from Saturn's rings? I'm going to see if I have that one.

I think that the name of it was "The Wasters", but I am not sure that it was by Asimov.

 

[jcrocker]

Ah, Google says it was "The Martian Way" by Isaac Asimov.

Sadly we now know the ring fragments of Saturn are not in mile-wide chunks.

 

[Timerover51]

Ah, Google says it was "The Martian Way" by Isaac Asimov.

Sadly we now know the ring fragments of Saturn are not in mile-wide chunks.

So you go for a cubic mile water ice asteroid.

 

[wellis]

Someone in another forum I frequent said this regarding the article:

Not enough CO₂? Use CH₄ instead. Much better GHG, and there's plenty of it.

Would this be good for terraforming Mars?

 

[Enoki]

The problem is solar wind strips most of the atmosphere off the planet. If Mars either had a strong magnetic field or something that blocked most of the solar wind (moon or artificial structure), the Mars would develop a thick atmosphere.

https://www.youtube.com/watch?v=gX5JCYBZpcg

 

[aramis]

The part I wanted to quote was

""As a result, terraforming Mars is not possible using present-day technology,” said Jakosky."

Once we get some people there, we can either MacGyver a work-around or start improving the technology.

Or import a few frozen carbon dioxide icebergs from a handy location.

Anyone remember the name of the Asimov story that had Mars settlers go get water ice from Saturn's rings? I'm going to see if I have that one.

We ARE already capable of moving asteroids. We just don't have a good reason to do so, nor a way to do so quickly. Dropping some dirty snowballs into a very low perigee and not terribly high apogee orbit can buff up the atmosphere. It would require a goodly amount of time... but needs nothing we don't already have: Ion drives, earth escape trajectory rocketry, and loads of time.

The bigger problem is, Mars is going to lose whatever we put there. If we were to add a cubic km of ice (in the gigaton range) we'd get about 31 years before it was all gone given the current loss of 1-2 kg/second. And that would not even be enough to affect pressure measurable, as it would be 1/25000000 the mass of atmosphere.

Having the tech to do something and having good enough tech to make it worthwhile are different.
Likewise, having the industrial base to do it is yet another obstacle.

We could, if we dedicated a large portion of Earth's industry, terraform mars reasonably for habitation in about 300 to 500 years, even assuming no new technology the entire time. But it's so improbable that it's unlikely.

 

[wellis]

So is it better to just build habitats on Mars than terraform it?

 

[Timerover51]

So is it better to just build habitats on Mars than terraform it?

I would say for the present, that would be the way to go. Water mining the Asteroid Belt might make sense at that point.

 

[aramis]

So is it better to just build habitats on Mars than terraform it?

Yep.

That, however, is also right on the edge of current technology.

We don't yet know how the reduced gravity will affect moderately large animals, let alone large primates. All the data currently is micro-gee or 1+ gees... and the higher gee mostly on birds and mice.

We really need to establish a suitable monkey habitat, and send them up for long term - longer than we can reasonably send people for - and see what lunar gravity does. And do a surface spin hab for mars grav.

 

[wellis]

Yep.

That, however, is also right on the edge of current technology.

We don't yet know how the reduced gravity will affect moderately large animals, let alone large primates. All the data currently is micro-gee or 1+ gees... and the higher gee mostly on birds and mice.

We really need to establish a suitable monkey habitat, and send them up for long term - longer than we can reasonably send people for - and see what lunar gravity does. And do a surface spin hab for mars grav.

Could that work okay? I mean would you be required to build a spinning part differently under gravity?

 

[aramis]

Could that work okay? I mean would you be required to build a spinning part differently under gravity?

you build it so that the combination of local gravity and centrifugal "force" combine to the desired gravity.

to simulate martian gravity on luna, you need 3.711 m/s²
Lunar gravity is 1.62 m/s².
Plugging in the numbers to a²+b²=c²

1.62²+b²= 3.711²
2.6244 + b² = 13.771521
b²=13.77152/2.6244
b²=5.24749314129
b=sqrt(5.24749314129)
b=2.29074074074

So... you spin for 2.3 m/s² radial, while in the 1.62m/s² vertical local gravity, and get about 3.71m/s², and want a slope of 2.3x1.62 I think the angle is 55° from horizontal. Anyway, you basically spin a slice of cone (point down) so that everything on it points directly "down" when spun. This can be essentially a train in a tubular track, or a whole spinning top suspended, or even a merry go round with a slanted deck at the rim.

 

[Nathan Brazil]

What about Valles Marineris ? I looked it up. It is 23,000 ft deep. Would atmospheric pressure be significantly more at the bottom like a Type F (thin, low) atmosphere, to retain other elements? Ya, ya its not a big planet, but that is fairly deep.

Just asking...

 

[Barrel]

you build it so that the combination of local gravity and centrifugal "force" combine to the desired gravity.

Yes, vectors.

 

[Condottiere]

Terraforming within a reasonable time frame, otherwise you might as well just chuck a Theia sized planetoid at Mars and wait a couple of million years, which probably would resolve gravity and magnetic field issues.

 

[BRJN]

Larry Niven chucks an ice-teroid at Mars to raise the water vapor percentage, in Protector (a Known Space novel). I don't remember that he used any math on it.

I suspect the terraforming of Mars will be done by accident, by pollution from local industry and agriculture, rather than according to any plan. If there is a plan, it will have to aim for 'mountaintop ' conditions not a temperate shirtsleeve environment.

 

[aramis]

Larry Niven chucks an ice-teroid at Mars to raise the water vapor percentage, in Protector (a Known Space novel). I don't remember that he used any math on it.

I suspect the terraforming of Mars will be done by accident, by pollution from local industry and agriculture, rather than according to any plan. If there is a plan, it will have to aim for 'mountaintop ' conditions not a temperate shirtsleeve environment.

Niven didn't have the facts needed to do it.

Still, ice-asteroids to Mars is going to be the way to give mars an atmosphere of any benefit. Many, with solar sails.

The problem being that it then needs a solar wind shield... an equitorial ring, which is a bit, but not a lot, beyond current capabilities, with a large magnetic field and it's own power sources....

 

[Enoki]

While we probably don't have the means right now, the easiest way to get an atmosphere on Mars might be to build several nuclear reactors on the planet and use these to generate gigawatts of electricity. That electricity would then be shunted through a series of cables laid around the planet, or in large loops as required, to produce a strong magnetic field.
The magnetic field would then shield the planet, or a portion of it, from the solar wind. That would in turn end the solar wind stripping the atmosphere away and give it a chance to thicken.
Mars would warm and that would make the planet far more habitable.