At the recent Starmus Festival, Stephen Hawking expressed some interesting ideas worth exploring. They are nothing new, especially for Hawking, but he seems to be speaking with more urgency on this issue. Essentially Hawking thinks that the human species needs to spread out off the Earth if we are going to survive long term. Here are his specific points:

• The Earth is not sustainable, and so we need to spread out.
• The Earth is at risk and therefore spreading out to other worlds will be a hedge against extinction events, like asteroids.
• Exploring the solar system and beyond will unite humanity.

He specifically recommends colonizing the Moon and visiting Mars (apparently with longer term plans for colonization). I partially agree with Hawking. I tend to disagree with him on the first point. To be fair, he does say we need to tackle global warming and take care of the Earth, but he also seems to be pessimistic about our chances. He also mentions that he is talking about surviving for the next million years, and so he is talking long term.

I don’t see the options of taking care of the Earth and spreading out to other worlds as an either-or proposition. We should do both. I am also more optimistic about our ability to live sustainably on the Earth. In fact, we need to, and if we don’t spreading out will not solve the problem.

The Earth is by far the easiest location on which to live sustainably (at least for humans). If we can’t make it here, we have no chance on the Moon or Mars. The Earth will remain our best chance for thousands or perhaps tens of thousands of years. Even then, the best case scenario is that we find or make another Earth. Whatever challenges we face one Earth, we will face there also (probably more so).

We need to figure out how to live on this planet without using up all its resources, destroying ecosystems, and radically changing the climate. We need to source our energy and food sustainably. We can do it, and we already have the technology, with only incremental advances, to make it work. We will probably see more than incremental advances. If, for example, we figure out how to harness fusion energy, that would entirely change the game.

Moving on – I completely agree with the second point. Although I think we should protect the Earth from asteroids, CMEs, and other similar threats, we can’t guarantee that a catastrophic event won’t happen sometime (especially if we are talking about a million year time frame). So yes, if humanity is spread out to multiple worlds, and multiple systems, our collective chance of survival long term goes way up.

However, since we are talking long term, there is no rush. It will likely be much easier to colonize other worlds in a hundred or thousand years. The probability of an extinction event in that time frame is tiny, so rushing to do it before we are technologically ready is not necessary. I am not saying we are not ready – I think we should absolutely go back to the Moon and plan for a permanent presence there. We have all the technology we need for that.

Mars is a more difficult question. We don’t, actually, have the technology we need for that. We don’t have the ships with the requisite shielding, and it’s not clear how a colony would survive on Mars. I am not saying that we can’t do it. But this would require a dedicated program, lots of resources, and the development of new technology to make it happen. I think our prospects of colonizing Mars at this time are marginal – possible, but highly risky. The Moon is a much better bet in the short term, and doing so would probably help advance the technology necessary to give a Mars colony a better chance.

Will space exploration unite humanity? That’s hard to say, but I don’t hold any Utopian views of a future of one united humanity sharing the solar system. I think the show, The Expanse, has a greater chance of being closer to the truth. In that vision of the future, humanity colonizes the solar system, but this just leads to new divisions and conflicts. Sure, the Earth might be united, but now we are fighting with Mars and the Belters.

But I do think Hawking has a point. The International Space Station does show the potential for space programs. Colonizing the Moon or Mars would take more than the resources of one nation. It would encourage us to work together, which means we will have stakes in each other. If we start with the joint understanding that “space” belongs equally to all humanity, and stay true to that principle, exploring space can be a uniting endeavor.

It will not magically solve all our political problems, but it can help. Space exploration should be considered a human project, not a way for one nation to compete against another. Big projects like colonizing the Moon or Mars could serve that end.  I also agree with Hawking that space exploration will spark interest in science and technology, and help inspire new generations.

We should be working right now on international plans to colonize the Moon. We can begin sending people to Mars for exploration, but colonization should wait until after we have a sustainable colony on the Moon. I agree with Hawking on the fundamental point that this is worth our investment.