Elon Musk doesn’t have a fucking clue. He keeps punting the wildly techno-optimistic notion that, not only will we colonise Mars, we’ll do it within the next handful of decades. I find this overflowing with the naively exuberant “disrupt everything” style of SV tech optimism. That or some seriously good drugs.
On the other hand, I do agree with Musk, insofar as he echoes a sentiment that goes back at least as far as Tsiolkovsky: Earth is the cradle of Humankind, but one cannot live in a cradle forever. Or, to put it another way: If we don’t get some of us off this rock and living (sustainably, independently) on another rock or two, we’re screwed. In the long term, extinction of Life On Earth is guaranteed, whether by our own irreversible pollution of the biosphere, a flying giant space rock, runaway solar fusion reactor or something else.
For bonus survival points we’d want to have Humans living in more than one Star System. (Insert gratuitous Hotblack Desiato reference to how much Hotblack despises the Star System here…)
If we’re going to become a species with multi-planet tenancy (with a highly optimistic nod toward multi-system occupancy) then we have no choice but to learn how to terraform planets.
If we were to find a planet somewhere Out There with a breathable atmosphere and appropriate magnetosphere, it would, with a probability asymptotically approaching 1, already harbour a significant degree of life. That much O2 at the right sort of partial pressure almost certainly implies biological processes. Whether it’s multi-cellular life is irrelevant.
If there’s a biosphere (even one comprised solely of unicellular organisms) what right have we to terminate that planet’s own, unique evolutionary course?
Even more so if things have reached a level of multicellularity.
Interfering in any way with an active, independently evolved biosphere would be a crime of the highest kind. We’d make ourselves the malignant pariahs of the galaxy, committing a form of biocide/ecocide.
Not that that’s ever stopped Homo sap. before, but there’s certainly an ethical line we’d cross by occupying another living planet.
So the only planets we can occupy with a clear conscience are the lifeless ones, planets sitting sort-of comfortably in the local star’s Goldilocks zone, and within parametric reach of our abilities to terraform them into a place we can comfortably walk around outside without protective gear. I think Covid has demonstrated quite nicely that, in general, we don’t like being cooped up inside all the time.
So we’d better learn how to do terraforming.
And terraforming planets is something we can quite comfortably begin to figure out, with two quite nice experimental platforms conveniently close to hand, just around the corner in astronomical terms, even long before we figure out how to do any hypothetical interstellar travel. Mars and Venus.
There are challenges, and many of them. The chiefest of which is that both Mars and Venus lack that ne plus ultra of biological convenience, that planetary des res must-have: a magnetosphere.
Mucking about with creating/altering the atmosphere, temperature, orbital parameters of the planet seem like small beer against that problem, but hey! I’m no expert in planetary evolution or geo-engineering, so perhaps there’s an easy answer I’ve not hear about.
Come to think if it, their shortfall in the magnetic department may even be the very reason they’re lifeless, uninhabited whirling rocks.
There are dozens of imaginative thumb-suck proposals for how to go about geo-engineering Mars and Venus, some of them entertained and paid-for by quite serious organisations’ taxpayers, but one fairly serious point I’ve not seen raised is that, you do not want people living on the surface of some planet before you start chucking space rocks/ice balls/nuclear explosives/rock-eating bacteria about the surface of said experimental
Personally I’d regard Venus as a more suitable candidate for our first experiments in terraforming. At least it can hold on to an atmosphere by itself. I did read KSR’s “Terraforming Mars” series many years ago, but if there was a compelling argument for favouring Mars over Venus, I don’t remember it.
I do recall one proposal that revolved around bombarding Mars/Venus with large (comet-sized) iceballs for a century or so to nudge the planet into a friendlier, cudlier orbit whilst simultaneously introducing lots of water and energy into the atmosphere. Seems like a somewhat plausible idea, though it does suggest that we might want to get more probes out into the Oort Cloud so that we can build a better picture of the resources that might come in handy for terraforming (not to mention as a source of non-gravity-well-constrained fuels, propellants and ores which we’ll need as we build on our ability to Make Shit Happen In Space.) If something like that works, it might even serve as a prototype for shunting the Earth about a little to mitigate the shit we’ve done to our own terrestrial biosphere.
The point, I think, is clear: If we want to become a truly multi-planet inhabiting species, then some of Mr Musk’s ventures are likely to be helpful as stepping stones along the path. But we’re still a hell of a long way away from actually living on the surface of another planet as opposed to dwelling like troglodytes in what amounts to nothing more than a space-ship-that-doesn’t-fly. Talk to anyone who has spent a Winter in Antarctica or South Georgia what that’s like! It’s a fine research station, but it’s not a life.
If there’s a moral to this, I think it’s that we’d better get serious about taking better care of the biosphere we already have (and didn’t need to spend gazillions on engineering) — the one that gladly and abundantly supports and nurtures us if we’ll just give the rest of the ecosystem a bit of elbow room, too.