why we need to forget about terraforming
Science fiction and popular science say that we can change other worlds to be like ours. In reality, that will be a terrible idea.
Back at the turn of the previous century, it was common to see men dressed as carnival barkers in monochrome pull a wagon into a public square, whip out a bottle of strange, dark liquid, and start their pitch. "Come one, come all! This miracle bottle treats diarrhea and diphtheria, tames halitosis and cirrhosis!" they hollered to many a credulous ear and unloaded their entire stock before quickly taking off for the next town. The elixirs and potions didn't actually work, you see, and they had to make a run for it before their customers got wise to this fact.
Today, we know them as snake oil peddlers, since many sold extracts from literal snakes, and the term "snake oil" is synonymous with a scam that promises something it can't deliver. Sadly, the snake oil racket lives on to this day, with impossible and ridiculous claims wrapped in thick blankets of technobabble, and no field is immune from having its own version of trendy snake oil. For computer science, it's the idea of uploading brains to computers. For fitness, it's calorie counting. And for space exploration, it's terraforming.
Numerous sci-fi novels and popular science documentaries have promised us that we could turn Mars into a second Earth. Some ambitious scientists also floated the idea of making Venus our even more habitable and hospitable twin given its close match for our gravity and orbit within the habitable zone. We've even gotten detailed thousand year plans to cool or warm atmospheres, seed new oceans with bacteria that will fill alien air with oxygen and nitrogen, and even to build the equivalent of planetary air conditioning units. Too bad it almost certainly won't work.
when terraforming plans meet reality
Despite being supposedly a prime candidate for transformation, Mars may be impossible for us to terraform with anywhere near our current level of technology, and woefully impractical and pointless with far more advanced craft and machinery. It literally doesn't have enough material to create anything more than a paper thin atmosphere, and creating enough of a magnetic field to hold on to it would waste tremendous amounts of energy because Mars is simply too small to ever support a habitable environment, natural or artificial.
Any change will be fleeting and all we'll end up doing is turn a frozen, toxic, nearly airless desert a tiny little bit less frozen and toxic, with a tiny bit more pressure for a few decades. And even if we constantly terraform Mars to keep it habitable, its low gravity coupled with still far higher than normal radiation will cause serious immune problems for any humans to the planet's surface. If the best case scenario means residents with fragile bodies and notably shorter lifespans, and a perpetual megaproject required to keep them that way, maybe it's best not to even start.
Things are even more complicated with Venus because its atmosphere would have to be frozen, then ejected into space until it coalesces as a moon, and have a new one shipped in, along with brand new oceans, from the ice moons of the outer solar system. And even after all that, you're going to have to deal with a planet that has a day longer than its year and will cook into a sterile desert should a delicate alignment of the giant mirror array required to manage its temperature fail after a meteorite impact, as well as lacking a magnetic field. It would be a better outcome than Mars, but not by much.
we'll need to think differently about space exploration
Humans are so used to customizing environments for maximum profit or efficiency, that it seems like changing other worlds would just be a bigger and more deliberate version of what's currently happening on Earth. But we evolved on this planet and our entire tech tree is here, advantages we won't have on other worlds. Every planet finds its own homeostasis, and upsetting it takes millennia and a vast resources on top of it usually being a terrible idea because it destabilizes the planet's normal balance to which it will always try to revert with every equipment malfunction or mistake in terraforming upkeep.
What does all this mean? In simple terms, if we ever decide to go forth and settle Mars, Europa, Titan, or a world around an alien sun, we will need to profoundly change ourselves with genetic engineering and biocompatible machinery. We'll need to find ways to resist changes in gravity, defend ourselves from radiation, extend our lifespans, and amplify as many of our innate talents as possible to become the galaxy's ultimate generalists. Rather than expect to change worlds and solar systems in our image, we should aim to feel at home in any terrestrial environment.
None of this is an admission of defeat. We should still make the decision to reach out into deep space and stay there. But we should do it realizing that in tens of thousands of years humanity will become a very different species that merges with sophisticated technology to adapt bizarre, alien shapes, sailing the stars in sleek, skyscraper-sized craft driven by quantum distortion fields on a never-ending quest to go further, knowing full well that our goal will be not just to survive on strange new worlds, but to find and appreciate their beauty along the way.
