To Mars or Bust - The Naiveté of Terraforming
(Originally posted April 19, 2017 on Blogger)
This is part three in my ongoing series, To Mars or Bust; a series of blogs I've been writing that put the brakes on what I see as overly-enthusiastic desires to colonize Mars. I am one of the few who isn't on the Mars-colony bandwagon, but I suspect in the coming years, my against-the-grain-but-with-the-flow-of-science stance will be vindicated; and hopefully by common sense, not because of a tragedy (immediate or long term). In time, I hope more and more people will come to realize that Mars is not suitable for colonization, much less for terraforming. Exploration; absolutely yes! It's important those reading this series distinguish between going to Mars to explore, and going to Mars to live, or worse, try to alter the planet.
Until then, this lonely series will remain a pariah in the Mars blogospheres. But I'm ok with that. I'm no expert on anything, nor am I proudly posting these blogs in some hyperbolic delusion of grandeur. I am very simply taking what I can easily argue is an ethical stand against sending well-meaning, starry-eyed colonists to Mars. This includes the good people from around the world who have had the misfortune of being selected for the Mars One suicide mission.
A quick recap for those who might be interested; In part one of this series, I provide a handful of reasons why colonizing Mars is fundamentally asinine. I then give reasons why manned missions to Venus makes far more sense. If we must send people to another planet, Venus makes the most sense for reasons pertaining to cost and human health to generalize a few. For those who haven't read part one and are interested to, you're most welcomed to read it here: To Mars or Bust - Pt. I
In part two of this series, I focus on the types and ill effects of ionizing radiation exposure that would-be pioneers to Mars will have to contend with. In context and comparison of that, I then provide yet more reasons as to why manned missions to Venus make more sense. For those interested, you can read part two here: To Mars or Bust - Pt. II
In this blog, I want to address notions of terraforming Mars as they pertain to both science and philosophy. As I have no outline, I'm guessing I'll likely touch upon the topic of colonization as well.
Though it seems many attribute the idea of terraforming to the proliferating red weed described in H.G. Wells' influential novel, War of the Worlds, the reality is, that red weed was little more than a unintended stowaway on an invading Martian spacecraft. In the novel, it wasn't the intentional terraforming tool that the Tom Cruise movie made it out to be.
I suppose the roots of planetary engineering can be found in religion, wherein only gods had the power to transform the world as they saw fit. But by the 1960s, people started imagining ways to do it themselves, beginning with Carl Sagan's idea for engineering the harsh global environment of Venus by initially seeding its atmosphere with algae.
In the 56 years since, ideas for terraforming other planets have come and gone in the many worlds and minds of and in science and science fiction literature. I was first introduced to the notion of terraforming in the early 1980s when I saw the movie, "Wrath of Khan". For those who haven't seen the movie, it's Star Trek meets a less-diverse version of the Village People in an epic space battle revolving around a terraforming 'genesis torpedo'. When launched at a lifeless planet, and upon impact, the torpedo would create a genetic explosion that rapidly terraformed the target planet into a habitable world lush with life. I have to admit, that's very clever of you Hollywood... a torpedo that genetically explodes upon impact... a double entendre torpedo... Genius.
But movies and novels aside, the idea for terraforming has taken a more, um, "serious" turn in recent years. Proponents like Elon Musk, and even some scientists at NASA, have been postulating ideas to change Mars from the barren "desert" planet it is now, to a lush planet in the not-too-distant future.
Musk proposed the idea of detonating a series of thermonuclear devices over (not on) Mars' permanent polar ice caps every several seconds in order to melt [sic] the frozen carbon dioxide and water in these regions. As these gases, um, 'melted' they would enter Mars' thin atmosphere as greenhouse gases (GHGs). Over time, they would hypothetically warm the planet surface via processes I explain in some detail in this blog.
Let's put Musk's radical idea into perspective.
A one-megaton thermonuclear device is capable of creating a fireball (here on Earth) of about 135 meters in diameter just milliseconds after detonation. This fireball would expand rapidly to just under 2 km by about tenth second. With 30-50% of the total energy released after detonation going into heat energy, initial temperatures could reach tens of millions of degrees Celsius.
As the fireball rapidly expands, it rapidly cools. This is the unavoidable cost of playing by the rules of thermodynamics. As such, another thermonuclear device will need to be detonated within 10 seconds of the first to keep the heat going. This sequence of detonations would have to continue, not simply at a single location over the caps, but across the expanse of the caps which are hundreds upon hundreds of square kilometers..
To detonate a single weapon, er, genesis device, over a single location would be a complete waste of time and money for a couple main reasons. One, a single blast won't be enough to liberate all the CO2 locked up in either polar cap. Two, whatever was liberated will collapse back to the surface in short order. Hence the need to detonate numerous thermonuclear devices simultaneously over hundreds of square kilometers, repeatedly for who knows how long.
With so many 'genesis devices' going off in Mars' ultra-low-density atmosphere (wherein what would have been blast energy here on Earth would largely go into ionizing radiation on Mars), I suspect there will be quite a bit of radioactive fallout. This fallout, including but not limited to radioactive, bone-seeking strontium-90, will blanket the Martian surface, mix with its electrostatic, toxic perchlorate-mixed dirt that kicks up in biennial global dust storms, and create what I'm sure will be an absolutely wonderful environment in which to send would-be colonizers.
As far as "melting" goes, I'm sure Elon meant subliming. The water locked up as ice in the polar caps on Mars exist at pressures below the triple point of water (611.657 Pascals). As such, when water ice is heated at that relatively constant pressure, it will convert directly to water vapor, skipping the liquid phase (ergo the melting process) entirely. CO2 will likewise sublimate.
All that aside, Mars' polar caps are quite expansive, particularly the roughly 1,100 km diameter northern cap. We'll need a lot of nukes to cover that area. The northern cap is an interesting place to say the least. An annual meter-or-so-thick layer of frozen CO2 (dry ice) forms during the Martian "winter", when the planet's northern cap tilts away from the Sun. When this happens, the northern cap falls into a months-long shadow during which time temperatures drop dramatically. As a result of these lower temperatures, CO2 freezes out of the thin atmosphere and falls as snow-like flakes to the surface, not to be sublimed again until the Martian "summer" months later.
While the northern cap is expansive, the southern cap by comparison is relatively small. However, despite the southern polar cap being smaller in diameter (~400 km), it still contains vast amounts of frozen CO2. In fact, according to data sent back from the Mars Reconnaissance Orbiter, just one of the larger dry ice deposits in the south polar cap contains between 9,500-12,500 cubic kilometers of solid CO2 (Phillips et al., 2011).
Moreover, there are two additional layers of dry ice sandwiched between ~30-meter-thick layers of water ice. Unfortunately, because these deeper frozen CO2 layers are sandwiched between layers of water ice, they fail to sublimate during the southern "summer" months. Not a problem, a few hundred thermonuclear detonations could solve that dilemma.
We'll get back to nukes and all that frozen CO2 shortly, but first I want to explain why I put "summer" in quotes because it sort of sets the stage for what I hope to get to later. Widespread claims that Mars has seasons similar to, or just like Earth's, are both true and misleading. From a dynamics point of view there are some similarities, but Mars' low-density atmosphere just can't trap the same energy as the systems we experience here Earth.
It is true both Earth and Mars have similar tilts relative to the plane of the Sun's equator (Earth's is currently at 23.5°, and Mars is 25°), but some fundamental things like temperature and wind simply don't feel the same in an atmosphere that is less than 1% the pressure of our own planet.
Temperatures and wind speeds are relative things when it comes to what our experiences would have us know. Consider winds for example: due to Mars' low thermal inertia, the planet surface can 'warm' up relatively quickly in sunlight. In very basic terms, the varied topography of Mars results in differential heating, and this results in pressure variations across the planet. Winds develop as air from relatively higher pressure regions moves towards regions of lower pressure.
We've all seen the famous dust devils of Mars; these form as "warmer" air near the surface is displaced upwards by a column of cooler air above. If conditions are just right, this rising air can begin to rotate. No one seems to mention that these seemingly innocuous dust whirls are filled with electrostatic, toxic perchlorate-rich dust particles. I'm sure this will make life on Mars an absolute blast for our colonizing pioneers who might find themselves befuddled as to how to keep the ultra-fine dust particles (<5 μm) from getting into their habitats & ultimately into their lungs.
But Martian dust devils are nothing compared to one of those, ahem, 'strong' roughly biennial near global Martian dust storms. Any Mars explorers on the planet during one of these events will find themselves changing their habitat's HEPA filters ad nauseum.
Winds from these "storms" can reach an impressive 60 mph, but these winds pale in comparison to the speeds attained by winds generated from sublimating CO2 at the polar caps. In these higher latitudes, winds can reach a formidable ~250 mph as they descend off the residual caps into vast and deep craters; similar to katabatic winds here on Earth but much faster. It all sounds quite impressive, but wind speed alone is not an indicator of force (wind load).
When wind is blocked by a surface (like a person, a landing module, etc.), the dynamic energy of that wind becomes realized as pressure, and that pressure (a force). To figure out just how much force a 60 mph, and 250 mph wind on Mars produce, we'll need to know a few parameters. One important parameter is the average surface air density, which on Mars is 0.020 kg/m3 as compared to Earth's 1.225 kg/m3. We'll of course want to know the wind speed (some say velocity, but who cares what direction the wind is blowing), and area of the surface that wind is interacting with. The acceleration of gravity is important too, which I'll get to shortly.
Let's take the human body as our first example of a surface in the wind; let's say it's Captain James T. Kirk from Star Trek. He is just under 6 feet tall (~1.8 m). He's gotten a little wider over the years, but let's say he's about 18 inches wide (0.46 m). We only need to know his two-dimensional area since only one side of him can be facing the wind at once. Therefore, his surface area is about 8.9 sq ft.
If we convert Kirk's surface area, and wind speed to the much better metric system and do some calculations, then it turns out in a 60 mph wind on Mars, Kirk would experience a wind load of about 5.95 Newtons. That's about the same amount of force as what he'd feel facing a 3 mph breeze here on Earth. Not very impressive.
But what about those ~250 mph winds that spin off (due to Coriolis effect) the polar residual caps? If we run those numbers, turns out Kirk would be dealing with a whopping 103 Newtons... or about the force of a 15 mph wind here on Earth. Sure, Kirk will weigh about 38% of what he'd weigh here on Earth, but even at a lighter weight, he's still not going to be blown over any more than the lander in the movie The Martian would... even in 250 mph Martian winds.
Some key reasons why dust storms on Mars look so impressive despite the low-force winds, is because the average sized dust particle is merely 3 µm (Lemmon et al., 2004). These tiny grains can be lifted by modest wind forces because they're in an environment where the acceleration of gravity is a mere 3.711 m/s², and the atmospheric density is extremely low. According to astronomer Suniti Karunatillake, even relatively larger particles (up to 20 mm) can become suspended in the Martian atmosphere by modest winds.
3 µm dust particles is really small. It's only slightly longer than the diameter of a DNA alpha helix (not counting repeating structure along the helix axis), but shorter than the diameter of globular protein. The reason I point these biological comparisons out is because I want to allude to the fact that these dust particles pose a genuine risk to would-be colonists' lungs and thyroids (if it contaminates water supplies).
Future colonists will find it tediously difficult to keep toxic Martian dust out of their habitats (Habs) and out of their lungs; especially if they intend on venturing out to do field work which would likely be a paramount mission parameter. They'll certainly need far more thorough decontamination procedures than what was depicted in the movie, The Martian. And on that point, hauling bucket-loads of that dirt into the Hab like Mark Watney did is, well, not too bright (see caption below).
But enough about winds and toxic electrostatic micro-dust, and the terribly over-simplified chemistry and crummy science of that Martian movie; let's get back to nuking the caps and freeing up all that CO2! A nice segue since it's equally dumbfounding (to me). But I'm no expert, so must admit that I can be easily dumbfounded!
Where were we? Ah yes, the southern polar cap. I apologize to my readers; I don't create outlines and just start writing. This makes my blogs kind of wander a bit. I really need to start making outlines, and will... I promise! After this blog. :) Anyway, with all the available CO2 locked up in the cap, we'll most certainly want to nuke it in order to liberate it to the atmosphere where it can help warm the planet up to livable conditions. To do it right, and as mentioned above, we'll of course need to nuke the entire expanse of the southern cap such that we adequately sublime its vast reservoirs of dry ice. We'll want it all in the atmosphere if possible. If we can sublimate all of the CO2 locked up just in the southern cap alone, then we could nearly double Mars' atmospheric pressure (Phillips et al., 2011). That sounds impressive, but isn't.
An almost doubling of Martian atmospheric pressure equates to a mere 10.5 millibars (as compared to an avg 1,013.25 mbar here on Earth). Rounding up, this means Mars' atmospheric pressure would increase from about 1% that of Earth's atmospheric pressure, to about... 1% that of Earth's atmospheric pressure. If that sounds redundant, it's because it is. Releasing all that CO2 isn't likely going to do anything more than make the news and inspire more innocents to commit suicide by Mars by volunteering for missions like Mars One.
It's important we not lose perspective on the fact Mars' atmosphere is about 1% that of our own. It isn't something that should be glossed over. It's a big deal. And though attention-getting headlines such as, "25-30% of Mars' atmosphere is locked up as ice in the polar caps", or "Releasing all the CO2 locked up in the southern cap alone would double Mars' atmospheric pressure" are factual, the figures being touted are nonetheless relatively insignificant in the grand scheme of things. That 25-30% is 25-30% of 1%. Kind of underwhelming. :( And as I expounded upon in this blog, facts presented out of context may be true, but can be incredibly misleading.
Some have proposed directing comets into Mars, and sure we could direct a comet into Mars to increase its reserves of water and gases. lol But that's a pretty risky endeavor that takes a lot more energy than people seem to realize. Trying to move a trillion kg comet can take as much energy as the entire human population consumes in a year. And one comet won't be enough. I'd venture to say the multiple trips we'd need to take to the Oort cloud to collect these comets would take a hundred generations or more. Needless to say, folks on the ol' bandwagon should drop their high hopes for crashing comets into Mars. Besides, even if we could, there may be an ethical argument as to why we shouldn't. I'll get to morals and ethics later.
With that said, I suppose it's obvious to say that I'm not convinced that releasing all of the CO2 locked up in the polar caps--even with substantial amounts of water vapor--would be enough to warm the planet. Trillions of tons of anything sounds like a lot, but on a planetary scale--even a planet as small and lopsided as Mars--those numbers represent mere drops in a dented planet-sized bucket. I say lopsided because a close look at a topographic map of Mars shows the northern hemisphere having mostly lower elevations, and the southern hemisphere having mostly higher elevations. The cause of this crustal "dichotomy" is currently unknown, but one hypothesis is that it is the result of a massive impactor.
Also, we ought not forget the elephant in the room; Mars lost its atmosphere for reasons. The other elephant of course being, IF Mars ever had an atmosphere much thicker than it has now. I may get to that in a future post in this series. Anyhoo, the water and CO2 in the polar caps froze there for reasons. Mars is the way it is for reasons. It seems only logical to forecast the possibility that any gases sublimed from the polar caps will ultimately end up back where they started from eventually. I may be completely wrong to assume this, but it seems sort of analogous to fixing a flat by adding air to the tire without repairing the hole first... and not adding enough air anyway.
To be fair, we could double down and nuke the caps after we've set up GHG-emitting factories across the planet. The idea to set up GHG-emitting factories (or generators) on Mars is something Musk has also proposed, and he may be on to something with this idea. If there's anything humans (particularly ones in developed countries) are good at, it's generating greenhouse gases. That we can do.
Unfortunately, the cost of building and maintaining enough GHG-generating facilities that are capable of generating enough GHGs at a rate higher than the rate of atmospheric loss due to stripping and sputtering, may require the combined GDP of Earth's 195 nations. We'll have to transport everything necessary just to set them up, not to mention all the stuff we'll need to maintain them. That will require multiple trips to and from Mars that--despite impressive cost cuts from engineering advances at Space X--will become prohibitively expensive. Let's not forget that the budget at NASA is subservient to whoever is sitting in the Oval Office. Would be tragic to have the budget to operate and maintain these GHG emitters only to have funding stripped faster than the Martian atmosphere when another president takes office. Even if we could afford it, it'd be a centuries-long commitment that will more than likely end in complete failure. Talk about a bad investment.
And in the unlikely scenario that these factories didn't fail, I'd feel a lot of pity for those tasked with building and maintaining them. They'll be dealing with the onset of low-gravity-induced osteopenia by the time they've gotten started on this epic project. Though, I suspect whatever bone density loss they'll suffer will be nothing compared to the atrophy they'll have in their hammer-swinging arms.
Osteopenia and atrophy aside, given what we've discussed with Martian dust, we already know anyone going to Mars will risk thyroid issues if water supplies are contaminated, alveolar collapse of the lungs if perchlorates are inhaled, and aplastic anemia to name a few rather dismal effects life there may have in store for them. But like I said with the Mark Watney scenario above; they may be oblivious to all this after their prolonged exposure to radiation and when the occasional heavy dose of ionizing radiation from X-class solar flares snapping in their general direction makes them too dim-witted to realize they're withering away.
But it seems many folks on the Mars colony bandwagon (which is more of a roller coaster without safety harnesses if you ask me) aren't too worried about all this boring stuff. Let's just make an atmosphere and go! Or why even wait! Let's just go live there now as is!
Someone might justifiably say, 'But Rook, CO2 build up can occur on Mars precisely because it's a heavier molecule and can avoid being stripped from the atmosphere. Even some scientists have said this.' This is true, but needs some perspective like everything else "controversial" in science. Let's just assume there is enough to warm the atmosphere to begin with. Though scientists have hypothesized that this is one of the reasons Mars' atmosphere is CO2 dominate (95.97% of 1%), the reality is that no gas over Mars is immune from being stripped or sputtered off into space.
UV radiation from the Sun can break CO2 molecules into their smaller (lighter) components (carbon monoxide and atomic oxygen). The lighter oxygen atoms can, have, are, and will continue to be stripped from Mars' atmosphere. What's left behind are the relatively heavier carbon monoxide molecules. But even these molecules can be broken down into their constituent elements (atomic carbon and oxygen) when hit by high-energy photons. Once freed from their molecular bonds, these atoms risk being stripped away into the celestial abyss too.
There's just no point in entertaining ways to create an atmosphere until we figure out ways to protect what's left there now, and therefore, whatever we think we can create there in the future. It's the hole in the tire scenario all over again. Without a magnetosphere or at least an induced one like Venus', new atmospheres will simply be lost over time. It's that elephant in the room thing I alluded to above. Atmospheric containment is an issue would-be planetary engineers should seriously consider before duping the well-meaning, highly-inspired public into believing something is as simple as 'we'll cross that bridge when we get there'. Well, I find that sort of attitude upsetting, particularly when you see the bios of good, inspired, brave, and hopeful people like those at the following link, who are oblivious to what they're getting themselves into:
When we put a human face to the idea of colonizing Mars, it adjusts our moral compass a bit... Or at least it should. It's especially disturbing when people who come up with the ideas to colonize and/or terraform Mars are unwilling to go themselves, even going so far as to cite the inherent dangers as reasons why they won't! I'd put another facepalm picture here, but this blog has too many already.
On a lighter note my friends, there is some hope on the horizon! NASA has proposed an idea to protect the Martian atmosphere (and its surface) with a surprisingly simple concept.
They have proposed establishing a ~2-tesla-strong-magnetic-field-emitting satellite at Mars' L1 Lagrange point. Basically (and I mean really basic), the L1 Lagrange point is a specific point in space between Mars and the Sun (see illustration below). The idea is to protect any newly-formed atmosphere on the red planet from the stripping effects of solar winds. It seems impossible, but the numbers apparently work on this one. ...or do they? Below is an artist's rendition of how it'd work:
A 2-tesla-strong magnetic field would likely be enough to protect what's directly behind it from solar winds. However, as is often the case, artist renditions don't necessarily represent reality.
The artificial magnetic shield created by the satellite would be unidirectional, meaning it can only shield what's directly behind it from what is directly in front of it (as illustrated above). As such, it will do little to protect Mars' nuked, er, I mean new atmosphere from what would more-or-less be an omnidirectional solar proton flux at that point in space; an unfortunate reality created by higher-velocity protons relative to slower plasma blobs emitted from the Sun. In other words, inside the plasma blob, these protons would be coming at you from all directions. Also, the field would do little to protect the planet from galactic cosmic radiation (GCRs), which of course comes from all directions, with particularly nasty ones coming from somewhere in the Ursa Major direction. The best place, as it turns out, to generate a magnetic field to protect a planet, is in the planet itself.
A Fistful of Ironies
We should recognize the inextricable moral dilemma that exists when considering ideas to terraform a planet; particularly if the planet harbors any life. But even if it doesn't, we should consider the fact that we would be robbing future generations of potential knowledge Mars may have to offer in its current relatively pristine state.
Barren or not, Mars is pristine. Its geology, polar caps, and thin atmosphere likely hold many more clues to our solar system's deep past as well as clues to how planets can fall from life-supporting heights that may have some important implications here on Earth. Imagine all we could learn from a single deep ice core sample taken from one of Mars' polar caps for instance (best done before nuking them). Tinkering with the red planet before we've had the chance to truly investigate its myriad of unique treasures is short sighted.
One might say that it isn't like we're going to terraform Mars any time soon; perhaps, but NASA already has plans to send colonies of cyanobacteria and extremophile algae species to the planet. Contained or not, that could still be a risky endeavor. Perchlorates may be a nightmare for humans, but many microbes absolutely love the stuff.
I don't want to expound too much on the unabashed irony evident in the proposed scenario of a species fleeing its home planet with intentions to create and maintain a healthy environment on another planet, precisely because it has failed to create and maintain a healthy environment on its home planet... but, we have to admit... that's embarrassingly ironic. Consider this passage paraphrasing something from the NASA Administrator:
"Humans must colonize Mars to ensure our survival as a species, said NASA Administrator Charles Bolden at the opening of the Humans 2 Mars Summit at George Washington University...Colonizing Mars (and eventually other solar systems) is the only guarantee against extinction, Bolden said. Even if some other global catastrophe does not wipe out humankind, eventually our sun will burn out."
Yes, yes... We need to get out of here before the Sun depletes its hydrogen core and begins to expand into a red giant... in 5 to 6 billion years. And though he seems oblivious to the fact stars like our Sun get hotter through their lifetimes and as a result our planet will probably be uninhabitable in about 300 million years, that's still 300 million years for us to get our act together. Remember, we've only been around for 200,000 years or less. So in the meantime, perhaps we can do something to make our lives on the planet we have evolved on more sustainable. As far as I can see, the most Earth-like planet in our solar system is Earth, not Mars. Even Venus is more Earth-like than Mars as I've stated in earlier blogs in this series.
Fleeing a planet that may suffer a global catastrophe in order to colonize a planet that has already suffered a global catastrophe is, well... deserving of a slow sarcastic clap by the most annoying character on Game of Thrones:
It's not just NASA saying this sort of nonsense, Elon Musk has also stated that we need to be a "multi-planet species" if we are to survive. Even the great Stephen Hawking agrees. Well, I hate to be Captain Obvious, but the survival of our species starts here on Earth. Furthermore, it inextricably includes the survival of several million other species living here as well. Thinking of the survival of our species over geologic timescales is fine, a bit vain, but sure why not. But to do so while basically writing off the growing myriad of anthropogenically-caused environmental problems that face both us and countless other species around the globe, is birdbrained (and I mean no offense to birds).
I take it back, but only because I love owls. But it's still pea-brained to say the least (no offense to peas). If we're going to migrate to another planet, it will most likely need to be one belonging to another star system; one that has naturally evolved to be truly Earth-like; not "Earth-like" as in the planet GJ 1132b or worse, Mars. Getting a colony of humans to an extrasolar planet that actually harbors life will take some time. haha And once there, let's hope the planet's viruses and bacteria don't kill our colonists.
At any rate (pun not intended), given our current interplanetary speed record relative to the Sun, we're not going anywhere anytime soon. Indeed, at the rate (pun intended) we're going--and as I've written in my previous blog--we're not likely a species that will survive over geologic time, much less cosmic time. In all our technological advances, and of all the people on this planet who might fare best in a new truly Earth-like world, it'd be the most "primitive" of us. And I don't mean that in a derogatory way at all. In fact, quite the opposite.
A member of the primitive Sentinelese tribe on the Andaman Islands would have a much better chance of survival on another Earth-like planet than any of us. They've not lived with the crutch of technology as we have, and would be better equipped to adapt to the environment without the knee-jerk desire to submit the environment to their will; thereby risking a potential cascade of unintended environmental positive feedback loops as we've done and continue to do here on Earth. It's no irony that the ones who would fair best on another world are also the ones who've best adapted to our own as is.
ATMOSPHERE ALONE ISN'T ENOUGH
All the plans out there to terraform are right to focus on creating an atmosphere. After all, it's a crucial component to making a planet habitable. But as we discussed, few of those plans worry about protecting that atmosphere, and fewer still elaborate on how to maintain the sensitive balance of gases within that atmosphere. We're unable to do that here on Earth, which is ironically why some rather influential people feel we need to leave this planet to colonize another... where we will somehow figure out not only how to create an atmosphere, but maintain it as well. Am I the only one seeing the irony in this?
But to maintain an established atmosphere will require a planet full of plants and animals (not one full of gas-producing factories). Plants will need a soil to survive. And I don't mean a Mars definition of soil (finer-grained regolith), but an Earthly definition, meaning unconsolidated regolith mixed with minerals and organic matter. One that exhibits soil horizons, themselves derived from a host of physical, chemical, biological, and morphological interactions. A soil that is capable of supporting root systems.
We're in luck. Because with an atmosphere established, we can let natural chemical and mechanical weathering processes do their thing. Since many assume we'll be a species that can survive over geologic time, then we shouldn't be too concerned by the fact that these weathering process will take just a few tens or hundreds of millions years; mere seconds on the geologic timescale clock. Here on Earth it only took up until the Silurian for soils to form enough to support a rather paltry selection of plant life (things got better in the Devonian).
Once soils begin to establish across Mars, we can speed things along by bringing in spaceships full of plant and tree seeds. We'll want a wide variety, because as any first-year environmental science student can tell us, diversity is crucial to the sustainability of an ecosystem and mitigates potential catastrophes like the potato famine. Mark Watney, take note.
But as mentioned above, it takes more than just the mineral-rich guts of weathered rock to make true soil. It will also need a diverse network of soil biota; all those little organisms, from bacteria to worms, that live and thrive in the ground. Their fecal matter as well as any chemical or mechanical work they do in the soil is key. We'll also need detritus; the organic remains of dead plants and (eventually) animals. Over time the remains of dead plants will decompose, enriching their nutrient-rich guts to the growing soils.
Our species may survive over geologic time (haha), but I doubt we'll want to wait an additional few hundred million years for soil biota to evolve. So, we'll need to import them too, and hope they take. Though, importing a species to a foreign land is a tricky matter. There is the whole positive feedback loop issue to consider. We humans have a pretty dismal track record when it comes to tinkering with nature. We've introduced or eliminated certain species to and from ecological niches only to see our valiant efforts trigger an ecological cascade of primary, secondary, and tertiary extinctions.
But we don't need to worry about that, because to have a multi-species extinction cascade we'd first need to have multiple species living on Mars. Again, since we don't have time for evolution, we'll need to import them as well; a sort of interplanetary Noah's Ark powered by a few hundred Space X rockets each powered by a few dozen Raptor rocket engines.
I don't mean to sound facetious, but good luck to our future colonists in keeping those animals healthy (or alive) for their several-month-long journey to Mars. And once they arrive, we'll need a host of biologists, zoologists, and all sorts of other 'ologists to deal with the animals when they are unable to adapt to the low-gravity environment and refuse to mate, eat, or drink as their brains try to proprioceptively adjust to the new engineered environment. Talk about animal cruelty.
Ah, but there's more! If we expect to have any angiosperms (flowering plants)--and we will need them--then we're going to need bees to pollinate those beauties. Well shucks. This may be a bit of a conundrum, as there isn't a single scientist on Earth that understands the cause(s) of colony collapse disorder. I'd sure hate to import that. But who knows? Maybe they'll do better on a planet that doesn't have as much gravity, nor a magnetic field. I'm sure they'll just love that; as will other species from sharks to birds. Seems logical to conclude that if we can't figure out how to keep a planet-wide healthy population of bees here on Earth, then we're not likely to have much success on Mars. But what do I know? The more important thing is that we get the heck out of here before we completely ruin this place. Ya!
What's that? Sharks I say? Yes, we'll most certainly need keystone species in every niche if we expect a planet to sustain its newly-acquired, um, terraformation (is that a word?). They teach this stuff in first-year junior college classes.
I won't even go into the probability that Mars may never be "green". The best pigments in leaves for photosynthesis may be better off if they're tuned to longer wavelengths. I only know this because I've seen the correlation between available sunlight and seaweed pigmentation in the ocean; red at depth (meaning they absorb bluer light), yellow-beige midway, and green near the surface. The color of the seaweed, of course, being the light they're reflecting (not absorbing). Mars sort of lacks the same intensity of sunlight we enjoy here on Earth.
Point of all this is, we'll need a healthy Plant and Animal Kingdom on Mars if we expect to sustain an atmosphere with steady levels of key gases; oxygen of course being one of them. And these Kingdoms need to be diverse if they're to thrive and self regulate.
And speaking of oxygen, we'll want to be sure its levels hover around 21%. If it gets too high, then any wildfires will be, well, pretty wild and likely planetary in scope. Too low and our red blood cells will have a heck of a time coping. I suppose we could set up a bunch of Elon-Musk-envisioned-atmosphere-generating factories, and set a dial in them to maintain an Earth-like oxygen partial pressure of 160 mmHg.... oh, that's right, partial pressures will be different on Mars since the acceleration due to gravity is an osteopenia-inducing 3.711 meters per second per second. I keep forgetting... So we'll have to set the ol' oxygen factory dial to 159.6 mmHg instead. Ahh, much better. That oughta' *cough* work just fine.
Of course we run into that whole cost-of-sending-factory-parts to Mars bit. I'm sure we could mine the material we'll need from Mars itself in order to forge the stuff we'll need for factories. Of course, then we run into that whole cost-of-sending-mining machinery parts to Mars fiasco. Not a problem! We are a species gifted with the vision of blind technological optimism. Where there's a will, there's a will.
But none of that matters. Because where will we get all the oxygen from? According to one paper, it can be derived from perchlorates (Davila et al., 2013), but not nearly in quantities substantial enough to terraform the planet.
I briefly mentioned weather patterns; we may establish an atmosphere on Mars only to find out the natural weather patterns that form out of that new thicker, more dynamic atmosphere are less than hospitable. Thanks to chaos theory, we can't predict our own weather beyond a week as I explained in this blog. We can make some educated guesses as to what sort of synoptic climate systems might exist given Mars' similar tilt and rotation to our own, but Mars isn't Earth. No matter how much we wish it were.
Now some might say we don't need to wait millions of years for rock to weather under the new skies. Yes, we will for reasons I touch upon in this blog.
We could bring our own supply of soil and fertilizer from Earth, but it costs tens of thousands of dollars per kilogram to achieve escape velocity, plus whatever costs are incurred getting to Mars. Things can get quite pricey if this is what we need to rely on in order to get things going on Mars on a scale sufficient to sustain an atmosphere much less a colony or city (as Musk envisions).
To be fair, I will concede however, and admit that Space X has reduced this astronomical cost to $27,000 per kilogram with their Falcon 9 rocket, and may well achieve a nominal cost of a mere $16,500 per kilogram with their Falcon 9 Heavy variant. If so, then this would be an amazing advancement for our ability to colonize our newly-terraformed planet. We could perhaps grow as many as three peanuts in a kilogram of soil, making a peanut cost $5,500. Not too shabby. I'm sure Forbes' top 10 could afford that sort of Hors d'oeuvre while they're in the Martian hospital being treated for that pesky thyroid condition. That is, unless Mars is hit by a solar particle event, in which case they'd possibly die... along with the entire hospital staff.
I'm all for missions--unmanned missions--to Mars. I would love to see many more, particularly ones that might one day take ice core samples. I'd even be for manned missions to the red planet, IF, whoever is sending them there has worked out a way to better protect our astronauts from radiation both in flight, and while on the planet surface, and IF they have the means and finances to return them to Earth. Most don't talk about how much it costs to bring someone back from Mars. They only talk about how much it costs to send them there. Well, newsflash folks, it costs A LOT more to bring them back than it does to get them there.
At any rate, common sense, basic science, and a sense of humanity should be enough to set off alarm bells when people start talking starry-eyed about colonizing or terraforming Mars when we have been gifted a planet that we need far more than we'll ever need any other one. But what do I know?
As always, thanks for reading.