I’d read the blog post, and was skimming the comments when I saw a link to this Wikipedia page. That is a really long list of end of the world predictions. If you worry about the Mayan calendar or Nibiru or some other scenario happening soon, perhaps you can take some comfort in seeing that the vast majority of those predictions are already in the past.

The next one on that list, which is also the next I’ve heard of, is Ronald Weinland’s prediction of May 27 of this year. I’m not especially concerned about this, not because of my lack of piety, but because at this point there have been so many predictions that I can’t believe Jesus would take the trouble to issue a warning. I mean, why bother when pretty much everyone is going to ignore it for very sensible reasons?

The sad truth is that an actual end of the world event would probably be beyond our ability to do anything about. But there are cataclysmic events worth thinking about and planning for. Earthquakes, cyclones, volcanoes and tsunamis are all very real, and it’s certainly worthwhile to plan for them.

And then there’s something in between.

Eugene Shoemaker estimated that a meteor, asteroid or other space rock hits us hard enough to cause a Hiroshima sized explosion on average about once a year. If you’re wondering why nobody noticed before the 20th century it’s because most of those explode high up in the atmosphere, so there’s a bright flash and maybe a thunderclap and that’s it. (I’m pretty sure I saw one of those years ago during a Perseid shower. I was actively looking at the sky but it was so bright I probably would have noticed it anyway. People inside the nearby building were completely unaware.)

That’s terrifying to consider, because we’re only just getting good at spotting things like that, we’re still a long way from being able to do anything about it. As we study the Earth and the sky, it seems more and more likely that it isn’t a question of whether or not we’re going to get hit by something big enough to cause global catastrophe and mass extinction, but how long we have until it happens. Right now if we spotted something like that, even if we saw it ten years before it hit, we probably couldn’t do anything to stop it.

As scary as that is, the odds are good that we have a long time before the next impact. But that’s not an excuse to ignore it, that just means we have time to prepare. There are scientists right now trying to come up with good plans to deal with that situation. They could use a lot more funding, in my opinion.

This is, to me, the strongest reason for not only space exploration, but colonization. Whether by asteroid strike or nuclear war or the Sun expanding, eventually Earth will no longer be suitable for human life. If we haven’t spread out by the time that happens, it won’t just be the end of us, but also everything we’ve ever done. It’ll be the end of Van Gogh, Da Vinci, Picasso. There won’t be any more Shakespeare or Eliot or Pratchett. Mozart and Louis Armstrong and the Cure will all go silent. Not only will all this be gone, there won’t be anyone to remember that it ever was in the first place.

There was an episode of Doctor Who in which the time travelers went so far into the future that the stars had all gone out, and they found our descendants still living on a world of permanent night. Holding out against the dark. I loved the idea that we could survive so long. By their time, the Earth had been gone so long that it had probably been forgotten entirely.

I think that’s something to strive for. Not forgetting, per se, but surviving long enough that it’s likely. I can’t think of a better reason to lose sight of home.