Our Place in Space: The Wilderness

Hello, friends!  Welcome to Our Place in Space: A to Z!  For this year’s A to Z Challenge, I’ll be taking you on a partly imaginative and highly optimistic tour of humanity’s future in outer space.  If you don’t know what the A to Z Challenge is, click here to learn more.  In today’s post, W is for…


All month long, I’ve been telling you about how, in the distant future, human civilization will spread out far and wide across the Solar System.  At the same time, I have rather casually been declaring various places in the Solar System should be off limits to humans.  I feel perfectly justified in doing that after reading a certain research paper titled “How much of the Solar System should we leave as wilderness?”

I’m not going to summarize that paper in its entirety.  If you want to learn more, you can check out the links in the “Want to Learn More?” section below.  The main point I want to talk about, based on what that “wilderness” paper said, is that the Solar System is absolutely ginormous.  You may think you understand how big the Solar System is.  However big you think it is, it’s probably bigger than that.

As a result, we can declare insanely large swaths of territory and resources “protected wilderness” without inconveniencing ourselves.  The paper advocates for establishing a one-eighth principle, meaning that our future space economy should be restricted to using only one-eighth of the resources in our Solar System.  The remaining seven-eighths would be off limits.  To quote from the paper:

We are required, as a point of social ethics, to accept reasonable constraints upon our self-interest in order to meet basic standards of justice between one another and (arguably) between ourselves and future generations.  This is a precondition of having any sort of stable and lasting human society.  However, we will take it that a livable ethic for society at large cannot ask for too much.  More precisely, a reasonable social ethic cannot ask for anything so demanding that it is impossible, inconsistent with what we know about human psychology, or otherwise so demanding that it belongs only in the domain of private sacrificial commitment of a sort associated with political and religious ideals.  The one-eighth restriction may seem to fall foul of this constraint.

Yes, the one-eighth principle sounds very demanding and restrictive at first glance.  But, as the authors of that paper go on to explain, the Solar System is really big.  Even if we make some highly optimistic assumptions about how fast the future space economy might grow, it would still take centuries to use up a full eighth of the Solar System.

This wilderness paper is now one of my all time favorite scientific research papers.  It does make some important warnings for the future, though, and if you’re a fan of the kind of futurism I’ve been touting in this Our Place in Space series, I’d encourage you to check out the links below.

In the meantime, I declare that the rings of Saturn should be off limits to mining operations.  Let’s preserve the natural beauty of those rings.  Parts of Mars should be off limits as well—if we find alien life on Mars, perhaps the whole planet should be off limits.  Same for many of the icy moons of Jupiter, Saturn, Uranus, and Neptune—especially Titan, Enceladus, and Ganymede—and most extra especially, Europa.  Seriously, nobody mess with Europa!

Want to Learn More?

Click here to read “How much of the Solar System should we leave as wilderness?”

Or click here to read an article from Live Science summarizing the paper’s main points in less technical language.

Oops! I Learned Something Wrong About Io

Hello, friends!

As you may remember from a previous post, Io is my favorite moon in the Solar System.  He may not be the prettiest moon, and he certainly isn’t the most habitable.  I, for one, would never, ever, ever want to live there.  You see, Io is the most volcanically active object in the Solar System.  He is constantly—and I do mean constantly!—spewing up this mixture of molten hot sulfur compounds.  It gets everywhere, and it is totally gross.

But it’s also super fascinating—fascinating enough that Io ended up becoming my #1 favorite moon in the whole Solar System.  I’ve read a lot about Io over the years.  I thought I understood Io pretty well.  But I was wrong.  One of the facts in my personal collection of Io-related facts was based on a fundamental misunderstanding of how Io’s volcanism works.  Let me explain:

Io is caught in this gravitational tug of war between his planet (Jupiter) and his fellow Galilean moons (Europa, Ganymede, and Callisto).  Jupiter’s gravity pulls one way; the moons pull another; Io is caught in the middle, feeling understandably queasy.  I always thought this gravitational tug-of-war was directly responsible for Io’s volcanic activity.  But it’s not.  Recently, while reading a book called Alien Oceans: The Search for Life in the Depths of Space, I realized that I had some unlearning to do.

The gravitational tug-of-war has forced Io into a highly elliptical (non-circular) orbit.  This means there are times when Io gets very close to Jupiter, and times when Io is much farther away.  When Io’s orbit brings him close to Jupiter, Jupiter’s gravity compresses Io’s crust.  And when Io moves father away, his crust gets a chance to relax.  This cycle of compressing and relaxing—of squeezing and unsqueezing—causes Io’s interior to get hot, which, in turn, keeps Io’s volcanoes erupting.

This squeezing and unsqueezing action wouldn’t happen if not for Io’s highly elliptical orbit, so the gravitational tug-of-war with Jupiter’s other moons is still partially responsible for Io’s volcanism.  But the tug-of-war is not the direct cause of Io’s volcanism, as I always assumed it to be.

I wanted to share all this with you today because some of you may have had the same misunderstanding about Io that I did.  Hopefully I’ve cleared that up for you!  But also, I think this is a good example of how the process of lifelong learning works.  If you’re a lifelong learner (as I am), you may have favorite topics that you think you know an awful lot about.  But there’s always more to learn, and sometimes learning more means unlearning a few things that you thought you already knew.


If you’re an Io fanatic like me, I highly recommend Alien Oceans: The Search for Life in the Depths of Space by Kevin Peter Hand.  The book is mainly about Europa and the other icy/watery moons of the outer Solar System, but there’s a surprising amount of information in there about Io, too.  Apparently, if it turns out that Europa really is home to alien life (as many suspect her to be), then Io may have played a crucial role in making that alien life possible.