Colonise Mars to save the human race?

We've discussed the scientific argument for human space travel but what about the survival argument? Should we be considering the 'life-boat' scenario to allow us to exist beyond the lifespan of the earth? Chris Smith starts by asking Ryan MacDonald if there is more than science alone inspiring him on his one way mission to Mars.

Ryan - Well, I think the science is certainly one of the largest driving personal factors and this question of whether we're alone in the universe and, if there is life on Mars, do they share a common origin with life here on the Earth or is it entirely genetically distinct? That's a question that's driven my focus in the science for - well, for as long as I can remember really, it's why I want to work on exoplanets effectively. But I think...

Chris - Planets that are outside our own Solar System.

Ryan - Yes, exactly.

Chris - Yeah, distant planets.

Ryan - But I think it's also, there's the  wider picture, which I think is the inspiration factor, which we'll come onto a bit more later...

Chris - The idea that we can establish a home from home on another planet, so that if things really turn nasty here for whatever reason, we can bail out over there. This is sort of dubbed the lifeboat scenario.

Ryan - Well, the worrying thing is that we know from the fossil record that 99.9 per cent of all species that have existed on Earth have gone extinct at one point. And particularly, if we look at the discoveries we've made from statistics from the Kepler space telescope ,looking for planets orbiting other stars since 2009, it seems to be implying that there could be 40 billion Earth-sized planets in the habitable zones of their stars.

And yet, we've not seen any evidence to date of life elsewhere in the universe. So that could potentially mean that we're extraordinarily special. And so, I would argue that we have almost a moral obligation to protect not just ourselves, but life as a whole here on the Earth.

Chris - Jill, where does the politics sit on this?

Jill - With regards to the lifeboat scenario, that is one that's used often to justify the idea that we need to start colonising planets elsewhere. I would just say that I think there's a couple of political and ethical concerns here.

First of all, there are opportunity costs when we spend on going to other planets and it makes me a little bit uncomfortable, the idea that this makes our own planet is disposable or that we're giving up on it. So, I think although I'm generally in favour of space exploration and eventual colonisation, I think that we need to not forget our home planet and the value of that.

Secondly is this issue of the inherent value of landscapes and environments outside of Earth and our obligations to them. So, if we go to a planet, I think there's a sliding scale of ethical obligations to them depending on whether or not it's a dead environment or if there's a biosphere with some sort of life, whether or not they're sentient life, intelligent life. But I don't think we should automatically assume the arrogance of, in order to need to preserve ourselves because we've caused problems on our own planet, on planet Earth that we automatically have the right to go out and colonise other planets as a backup.

Richard - Well, this lifeboat idea, lots of great people have said this. Perhaps Mars shouldn't be the ultimate destination though if you're talking about a lifeboat for Earth and maybe we should think of it as stepping stones. So you go the Earth and you keep the Earth because everyone looks down at every astronaut, all they talk about is not how great the moon is or how great the space station is because it's clearly not, it's how brilliant the Earth is when you look at it.

So let's not forget the Earth. That's really important, but maybe should look at stepping stones. So you say, "Right. We've got the space station" you then go to the moon, you then use the moon to Mars, you then maybe have some sort of giant starship, you start to look at ways of leaving the solar system. Because frankly, Mars is horrible. It's dead, it's barren, it's bleak, it's desolate, there's not enough sunlight. It's rusty, it's a grim place. You would not want to stay there for long.

But if you can use it as a stepping stone beyond that then the lifeboat starts making sense. You start talking about colonies that could leave the solar system and go out to the galaxy, and we could colonise the galaxy, colonise the universe.

Chris - Ryan, it doesn't sound terribly inviting as your future home, the picture that Richard is painting.

Ryan - Well surprisingly, Mars is actually the most habitable planet in the solar system apart from the Earth.

Chris - Haven't got many to choose from really!

Ryan - Just look say, the day on Mars for instance, it's 24 hours with an extra 36 minutes or so. So we don't have to do any incredible crazy engineering like altering the spin of a planet like you'd have to do on Venus.

Incidentally, you're not going to be set on fire immediately on the surface of Mars or be crushed by the pressure like you would on Venus either.

Mars crucially, everything we're learning about it seems to be suggesting that it was a more habitable planet around 3 to 4 billion years ago. Particularly, we've been learning this from Curiosity. And so, with regards to the legal implications potentially of - should we be modifying environments or landscapes on Mars, perhaps we should consider that what we're actually doing is just restoring and fixing Mars to how it was billions of years ago.

Chris - Jill, where do we stand on the idea of the picture that Ryan is painting which is, we go to Mars and we basically mess with it to make it more Earth-like?

Jill - There's a couple of things that come to mind. First of all, I think it's worth questioning who it is that we're going to be sending out with them and they would essentially be the vanguard of humanity. Do we want this to be done by countries or companies and so on?

The other thing is there is a legal infrastructure that's been in place since the '60s and '70s which establishes that outer space is neutral territory including celestial bodies. Specifically that nation states can't make claim to celestial bodies. I don't think that this is going to restrict potential future colonisation and I think that it's an infrastructure that we need to work within. It's governed by 5 main treaties, four of which have been widely ratified.

But we will need to start with unbundling what that means in terms of mining the resources, whether also individual countries are required to be responsible for the objects that are launched into outer space and have legal liability responsibilities in case things go wrong. If we've got humans up there, there's going to be issues like criminal liability. So, there's a lot of legal issues they're going to have to be unpacked and overlapped on top of this pre-existing deep legal infrastructure that we've had in place for the last 50 years or so.

Chris - Mind you if Carolin's robots take over then we may end up having to have robot courts. Carolin, just looking at the practicalities though, it sounds lovely. Let's turn Mars into a home from home by terraforming it. Is that reasonable? Is that scientifically plausible to do that on a scale of a whole planet?

Carolin - I guess it depends how much of a rush you're in. If it really is a lifeboat, well then I think we're a shot because it's going to take - I would guess - several millennia to happen. If you want to terraform a whole planet, you're talking about changing its climate, changing its surface. So not only do you have to thicken, enrich the atmosphere, you have to make it warmer, you need to perhaps introduce some greenhouse gas - methane, ammonia that warms up the carbon dioxide and thickens the atmosphere.

There's a lot that's got to happen and we could do it. I'm not saying it isn't technologically possible. I do share a lot of Jill's reservations about whether we should do it and just all of that.

But a key thing is that Mars does not have a strong magnetic field. It doesn't have the magnetosphere. So, even if you build up this wonderful atmosphere, you warm up the planet, you need to retain that atmosphere.

Chris - I was going to say, how do you stop that atmosphere being whipped away by the very process that has left Mars this prune of a planet that it is right now?

Carolin - As Ryan was saying, Mars was once a much more hospitable planet. It had this thick atmosphere. It had the volcanic activity. We even think it had a strong magnetic field but it doesn't now. And so, you're leaving this wonderful new atmosphere being stripped away.

So perhaps if you're really going to do it, maybe you are going to be terraforming Mars, but maybe not start off with the whole planet. Maybe start off with a few select biomes perhaps as Richarch's suggests, start off with the moon, find a nice crater near some resources, near some sunlight. Do the terraforming or try terraforming in a very local scale within easy reach of Earth and then moving to doing some similar things on Mars, building these biomes, doing things slowly rather than just wading in, and potentially, wrecking a whole planet because again, as Jill said, our track record on Earth isn't brilliant. So, we need to be very sure about what we're doing.