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There's a Hell of a Good World Next Door
31 December 2017


Image credit: U.S. Air Force

I am fond of Mars - honestly, who isn't? It looks a little like some parts of Arizona, the southwest U.S. state where I live, so at first glance it seems cozily familiar. The cultural history of Mars is rich; it has been a favorite science-fiction setting for more than a century. Most exciting to me, Mars might yet prove to be a home to life. We'll likely determine whether Mars lives by exploring the planet's delightfully complex geology. It seems probable that, if there is life on Mars, then it will be life in Mars. After all, much - some say most - of Earth's biomass lives deep within Earth's crust and has for billions of years.

There's no sense arguing the point: Mars exerts a powerful pull on the emotions. That being said, however, one has to exercise caution when emotions are part of  the mix (as they always are). The thought of humans on Mars is exhilarating. Should humans, however, actually set booted foot on Mars?

I think the answer to that question must be yes - eventually. Humans should travel to every place they can. As we gain experience, improve our technology, develop new spaceflight concepts, and mull over data received from our robotic proxies, we become more capable. As we become more capable, we increase the probability that we can achieve success.

By "success," I mean several things. There's the obvious one: we increase the likelihood that humans will survive the Mars trip without short-term or long-term injury and be able to perform meaningful exploration. We also increase the likelihood that we will avoid clumsily interfering with our study of any native living things that exist by introducing terrestrial biological contamination.

It would be really handy if we had a place nearby where we could prepare ourselves for journeys throughout the Solar System. A good-sized world with a range of alien environments and a complex geology. A world from which we might return rapidly if we got ourselves in over our heads. Bonus points for a world we can reach cheaply, using technologies we have at hand, and from which we can extract resources that could facilitate our journeys to more distant worlds.

All right, I know, I should just come out and say it. Most people realize that such a world exists. Also that it appears in the skies of Earth much of the time, and that, despite orbiting nearly a quarter of a million miles away, it has surface features visible to the unaided human eye.

Furthermore, it bears bootprints half a century old. Using technology shockingly primitive by modern standards, 12 humans walked, worked, and drove there. When they faced difficulties, they spoke with a support team back on Earth with a one-way radio time-delay of only 1.25 seconds. One mission suffered a grievous malfunction, but its crew was close enough to Earth that they were able to limp safely home.

I've expressed my opinions about this world before, calling it a part of Earth. Together with Earth, it forms a system unique in the inner Solar System. Mercury and Venus have no moons; Mars has two, but they more closely resemble middling-sized asteroids than they do planets. Earth, however, has as its neighbor the planet-sized Moon, a world which, were it a continent, would rank after only Asia in surface area. It is the fifth-largest moon in the Solar System; only Ganymede, Titan, Callisto, and Io are larger.

We have barely explored the Moon. Automated and piloted orbiters have surveyed its entire surface, but no functioning spacecraft has landed on the Farside, the hemisphere of the Moon we cannot see. Nor has any spacecraft soft-landed near its poles, where ice lurks in permanently shadowed craters at temperatures lower than those the New Horizons spacecraft measured at Pluto.

The ice at the lunar poles could supply rocket propellants for at least tens of thousands of years. Given the cost of establishing a lunar propellant manufacturing and shipping infrastructure, it would be a foolhardy to develop lunar resources only to accomplish Mars expeditions. It would be cheaper to use heavy-lift rockets to launch from Earth components of piloted Mars spacecraft with propellants already inside.

It need not always be so. By virtue of its low gravity - just half that of Mars and one-sixth that of Earth - and its lack of an appreciable atmosphere, the Moon could become an economical propellant source for an Earth-Moon infrastructure that might include habitats, solar power satellites, laser batteries for boosting solar sails, factories, spacecraft service stations, observatories with the resolving power to see continents on planets of other stars, and facilities no one has thought of yet. Many of these facilities could be manufactured at least in part from lunar titanium, aluminum, and glass. By the time that level of infrastructure was achieved, the propellants needed for piloted journeys to Mars would be an incidental portion of the total produced on the Moon.

Developing the Moon gives us time to try to determine, using robots, whether life exists on Mars. It buys us time to decide what that knowledge should mean for us and our posterity. As important, it creates many new options beyond Mars. Should we determine that long-term habitation of Mars is undesirable, the lessons we have learned and capabilities we have acquired in developing the Earth-Moon system could be readily applied to worlds throughout the Solar System. Think about it: Earth and Moon are more like most worlds in the Solar System than is Mars.

If Mars pulls on our emotions, then it is probably not too bold to say that the Moon pulls on our minds. Of course, people who value the Moon have an emotional stake in it. It seems different to me, however, than the exuberance would-be colonizers feel about Mars. I suspect that, if you have read this far, then you might see a difference, too.


Image credit; NASA

Source

The post title is a play on the last line of E. E. Cumming's short free-verse sonnet "pity this busy monster, manunkind," published in 1944. That line reads - "listen: there's a hell of a good universe next door; let's go"

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