The science of space exploration concerns itself with the idea that life is rare, possibly unique to our planet, and that we have the obligation to try and discover if it exists elsewhere. The opposite case is far more likely: life is neither unique, nor rare, and we are not alone.
The idea that humans should one day establish permanent settlements on other planets (both in our solar system and beyond) has been around since the earliest days of the space program – not to mention the earlier days of science fiction. Terraforming is the ultimate extension of this line of thinking, the spread of Earth-life to other solar systems which are probably barren of this precious commodity.
But what if we’ve had it all backwards? What if life is common in space? From this standpoint we soon find there are other, far more compelling reasons to wholly commit our society to the effort of setting up those futuristic, shiny colonies next door in the Alpha Centauri system.
There are other intelligent life forms out there in space. Accept it.
If you can’t get your head around this near-certainty, then you have no concept of the true size of space. This isn’t an abstract notion, like trying to prove the existence of God. We already know that intelligent life exists, because it exists here. So the real question we ought to be asking is what’s the likelihood that intelligent life exist elsewhere?
The answer depends, in part, on our understanding of just how many habitable planets there are. For starters, there are likely many thousands of them, if not millions, in our galaxy alone. By habitable I mean a planet roughly the size of ours, with a temperate zone about as warm as ours, and containing water.
This is without taking into account the possibility that life may exist under harsher circumstances than our own Antarctic plateau. For all we know, life is common in our galaxy, yet we almost always assume the opposite. As it stands, the ratio of planetary systems known to be capable of supporting life to those that actually do is 1:1. Every single one of those planets capable of supporting life may already be doing so. The odds that just one of them might have allowed the evolution of one or more intelligent species is quite high.
The counter-argument, of course, says that we don’t know life exists anywhere else, and so the contention that intelligent life exists elsewhere is simply stretching this unknown to its limits. Granted, nothing is certain, although with enough knowledge of a set of circumstances we can at least say that some things are probable. But let’s leave the millions of planets in our galaxy aside for a moment.
How many galaxies are there? No one knows. In 1995, the Hubble Space Telescope examined a fairly “empty” patch of sky for 10 days, and the compiled data was organized into an image known as the “deep field.” The image gave us an astonishing new insight. At last we could see, in concrete terms, what scientists have long believed: space is full of galaxies. A look at the deep field image shows innumerable points of light, each one of them a galaxy. Not a star, not a comet, not a cloud of luminous gas, but an entire galaxy. There are more galaxies in one small patch of seemingly empty sky than we can count. Each one of them composed of billions and billions of stars, with those stars surrounded by many more billions of planets.
There are more planets and stars in space than we can possibly imagine. Even if we were just to limit ourselves the regions of space we can see with our telescopes, the number is … pun intended … astronomical. Our brains simply weren’t designed to consider numbers this large, at least outside of the realm of mathematical abstraction. In this scale of reference, what seems unlikely to many of us – the notion that ETs do exist – becomes almost a certainty. It turns our entire frame of reference on its head, and forces us to re-examine the tottering foundation upon which we base our argument that our life-bearing planet is unique.
Why is it then that we can accept that truck-sized carnivores once roamed the earth, or that our planet was, at one time, a single giant landmass surrounded by a super-ocean, or that our complex multicellular bodies were formed from one microscopic cell – but we have difficulty with the idea, with the mere possibility, that we are not the only thinking, socially organized beings in all of space? There is every reason to believe that life is common, and that once it takes hold it tends to gradually adopt more and more complex forms – and we know this, beyond a shadow of a doubt, because we have seen it happen here.
It is ridiculous to suppose that we are alone.
It is better not to be colonized.
We tend to shy away from thinking about colonizers from space, for fear of ridicule. But to my mind, imaginative treatments of the subject, such as the 1996 alien disaster movie Independence Day, are right on the money. We have no reason to expect that visitors from other life-bearing planets will be well-intentioned. And we have every reason to expect that they are coming, sooner or later.
Or try thinking about “invaders from space” in this context: What happened to the aboriginal North Americans after the European colonists arrived? Or for that matter, what happened to the aboriginal Australians? The Aztecs? The Inca? The native inhabitants of Hawaii? The Eskimos?
You know the answer. They were conquered. They were wiped out by disease. The were pushed out or relocated to the literal deserts and wastelands of our globe. The few survivors adapted to the new, colonist-dominated society with much hardship. These surviving indigenous cultures became largely subsumed by the cultures of the colonists and explorers. This is not science fiction. These are the established facts of our shared history.
The colonizers, on the other hand, benefited greatly from their endeavors. They were introduced to new, valuable crops and livestock. In most cases they were able to thrive in unfamiliar terrain with the aid of aboriginals. Their explorations were greatly aided by native guides. They intermarried and intermingled with those they conquered, and broadened the genetic diversity of the mainstream population. It is a process that we can look back on and see replicated time and time again.
Of note is the fact that the colonized continent of North America became host to one of the more dominant societies on the planet. Colonization, broadly speaking, reaps great rewards for the colonizer; those who are conquered, however, suffer greatly. Knowing this about our own history, why is that we have set ourselves up for the very likely eventuality that we will one day be colonized from space?
Why are we likely to be colonized? Assume for the moment that my earlier argument is true, and that intelligent, technological civilizations are common. If space is infinite, or for all practical purposes, near-infinite, then it is quite likely that someone – perhaps many civilizations – are already exploring. Some societies are just developing, some are on the verge of space exploration, and some are very advanced. The advanced ones know what they are looking for, and they will have some pretty sophisticated equipment to help them search. What do they want to find? Most likely they are searching for the very same things we would want to find: habitable planets, useful, perhaps unknown resources, and other civilizations. They are not going to wait for us to cure cancer, or to solve the aids epidemic, or to eliminate poverty before they come. If they have the means to find us, and the means to get here, they will come.
Okay. Whoa. Hold on a second. Are we really supposed to be planning for space invaders? Bug-eyed monsters? I’m not so sure about bug-eyed monsters. ETs may be quite different from us, physically, or they may be similar due to the principle of convergent evolution. (The reason unrelated species, such as sharks and dolphins, happen to look so much alike.) But space invaders, yes: that’s exactly what we ought to be preparing for. Only we ought to be preparing by planning to meet them far from home.
Even if you reject the notion that the existence of an ET is a certainty, I should think you’d want to hedge your bets against being wrong. The consequences of being wrong are significant. The massive upheavals that took place in aboriginal societies upon being colonized would surely pale when compared to the disastrous consequences of having uninvited extra-terrestrials set up housekeeping on our planet.
Again we must think of this in terms of what happened during our own age of colonization. An alien race that gets here before we get there will have a better mode of travel (galleons to our canoes), better weapons (muskets and cannons to our spears and arrows), better communications (written text, as compared to word of mouth), greater scientific achievement (iron smithing and chemistry, compared to our stone-age technology), and a better understanding of the universe (map making, for instance, as compared to folklore and first-hand experience).
The reason our future colonizer will be better in all of these categories of development is precisely because they managed to explore before we did. Consider that most of the developments I touched on from our history became fully realized during the age of exploration: gunpowder, seaworthy sailing ships, map making and so forth. Successful exploration demands scientific progress and technological advancement. We also know that innovation flows strongly downstream in the wake of those exploration endeavors. The Apollo Program, for instance, brought us numerous advancements, including fuel cells, integrated circuits, and even cordless tools. Also, the race that can explore will learn from every society it visits, whether they are friendly or not. Sitting back and waiting, on the other hand, is a recipe for stagnation.
But the consequences of waiting to explore are not just a slowing of human progress. You just don’t want to be colonized if you want your civilization to survive – and your best defense against this possibility is to become a colonizer yourself. A society that has established many off-world colonies and has contacted and developed relationships with other advanced societies is much less likely to be colonized itself. And in some far-flung future, if we do choose to set up colonies on planets that are already inhabited, I should think we’d want to carefully consider the era of European expansion before we proceed. Surely we can move forward in our quest to expand with a greater degree of compassion and clarity than these so-called conquerors.
All action, including inaction, has consequences.
For the sake of argument, lets say we don’t follow this advice. We continue our study of space at the current rate – which is a notch above a near-standstill. In essence, we wait for our extra-terrestrial Marco Polo, our Pizarro, our Cortez, to show up at our doorstep. Like the aboriginals, we will surely be stunned by the arrival of our future colonizer. We will not understand them. We will be bewildered by their superior technology. We will underestimate their intentions – both good and ill – and there is still the great likelihood that even a benevolent colonizer will do us great harm. Smallpox, rampant alcoholism, and a dramatic upturn in violence were all “gifts” that were unintentionally passed on by European colonizers. We should not expect anything less from even the friendliest of visitors from space.
Arguably one of the most destructive traits the European colonists demonstrated was their desire to supplant the established theism of their aboriginal hosts. Evangelical fervor was typical of colonizers, and religious conversions were by no means always voluntary. Failure to convert often carried with it some form of torture or even a death sentence. Is there anyone who would not wish no avoid such an encounter? Or perhaps you would prefer to pray to an alien god.
My point in illustrating these risks is relatively simple: becoming determined colonizers of space is the best insurance policy we can buy for our planet, whereas the risks involved in doing nothing are immense. Why then, would we not make every effort to protect our global society against the possibility of its complete alteration or destruction? Our very lives, our continuation as a viable species, could hang in the balance.
Human beings have always been great explorers. Why have we halted our progress in an area that was thought to be our birthright? One might argue that it is in our genetic heritage to explore. And yet even when we have proven that we can venture beyond the admittedly significant boundary of our atmosphere and our planet’s gravity well, we seem to have forgotten this most ancient drive – the willingness and determination to explore beyond the visible horizon.
Some have argued that there is no point in having humans go searching beyond our planet’s orbit, out into the parts of space that can be more easily reached by satellites or other machines. Others contend there is nothing out there worth exploring. The moon is just a rock, after all. And yet others state with conviction the opinion that we ought not to go exploring other planets when we have yet to learn to take care of our own. The most common counter-argument has to be that there are simply more pressing issues demanding our attention here at home.
A short look into our past reveals that all of these arguments – or similar ones – were made at the outset of trans-oceanic exploration, when sailing ships were crude, uncomfortable, and barely seaworthy. It’s too dangerous. Too expensive. It won’t be profitable. There won’t be anything out there to find. We have an urgent need to focus on domestic affairs. These kinds of arguments did not stop us then, and they shouldn’t stop us now.
We are in the midst of a space race, a deadly serious one, only we don’t know it yet. The high probability that we will be colonized at some point in our future trumps all of these nay-saying arguments. There are certainly other compelling reasons to seek out the nearest habitable planets in our region of space, such as insuring ourselves against the event some unforeseen planetary cataclysm, or to protect ourselves against runaway global warming (as Stephen Hawking has cautioned.) But I find none underscores our need to explore with the same urgency as the notion that we may well be colonized by someone else if we don’t get up from our entertainment consoles and get out there soon.
Yet here we are just sitting on our splendid, remarkable planet Earth, waiting to be colonized. To those of you say the exploration of space is too costly, is not feasible, is too far-fetched, is a distraction from our myriad domestic crises, I say this: “May your Andromedean mind-control collar fit you well.”
It is better to explore early, and to explore in a sustained manner.
Once we accept the idea that a much more intensive effort to venture out into our galaxy must be adopted, we should first take a few additional lessons from history. First, we are kidding ourselves if we make the assumption that our rivals in space exploration are going to be friendly. Second, we are not doomed if we are slow off the starting block, as long as we do get started. And third, our strong tradition as explorers has prepared us well for this task.
Imagine for a moment our first alien contact is with a hostile race. I’m not just talking about an active colonizer here, but something more along the lines of the aliens known as the Borg in the Star Trek: Next Generation series:
Resistance is futile. You will be assimilated.
Before you laugh with incredulity at this picture, you need to take a look back over your shoulder. I don’t think anyone would argue that the conquistadors were not hostile toward the indigenous peoples of Mexico. As with the Spanish of that era, explorers are often hostile, and the subjugation of other races is one of the reasons they do explore. Many societies were built on the backs of slave labor, and it would be naïve to assume that all technological societies have outgrown the concept of slavery.
So there it is. We are unlucky in that our first, closest neighbor is an aggressive one. But as chance would have it, we have been at this space exploration endeavor for some time, and we have already colonized fifteen different worlds. It turns out that our adversary has colonized only two, and both are just at the beginning stage of development. Even better, one or two of our new planets already supports a population greater than that of our mother planet Earth. I think anyone can see the obvious advantages we would have in this situation, compared to our rival, even if they possessed somewhat better ships and weaponry.
Yet even if we are slow to branch out, this would be vastly better than not getting started at all. The Spanish and Portuguese were the first to develop the carrack-type of sailing craft – the first proper ocean-going ship suitable for long voyages of exploration. In 1500, Portugal made use of this superior technology to discover South America, and in 1519, Cortez, a Spanish explorer, landed in Mexico. But slow-starters such as France, the Netherlands, and Great Britain rapidly developed their own exploring potential as technology (including ship-design and maps) migrated northward. And in the end it was the British who emerged as the dominant global power during the age of sail.
Britain’s example serves to point out that we do not have to be the most advanced explorers from the outset, as long as we have developed a true exploration infrastructure in advance of the discovery of new, perhaps alien, technology.
It is time for us to reestablish our strong exploring tradition on this greatest of frontiers. We have no idea what we will discover, but like the audacious undertaking of circumnavigating the globe, or embarking upon a journey to the once unassailable peak of Everest, we must do it because the cosmos challenges us so. We must explore because it is in our blood. Because we have it in us to know what lies at the South Pole, because we have it in us to know what the dark side of the moon looks like, because in our hearts we know we want to ride the rocket, to ride the solar winds. In our hearts we know we were meant to boldly go.
Like the British, or the Dutch, or the Colonial French, we may eventually discover others out there who possess better technology that we want to adopt. We may discover that our earliest fears of hostility were wrong, and that other races of intelligent beings are more than eager to help us advance, and want to be our friends. There may already be an established community of cooperative societies, something like an interplanetary UN, but for the moment we are ignorant of its existence. The essential point is that we must ensure we make these kinds of discoveries out there, rather than to be discovered here – for reasons I have already outlined.
Overcoming the challenge
A final point is to emphasize that we have to be determined enough to overcome setbacks. The Cold War, as it turned out, was a boon to space exploration. We all know how the space race happened. The Soviets got out to an early lead, and the United States scored the touchdown – or at least this is how it has been popularized. But both societies got there, in some form or other, which is what really matters.
Thinking about the final outcome of the space race serves to underscore part of my argument. We have proof, on our planet, that different technological societies can develop the capacity for space travel. We must then assume that any technological society will surely develop this capacity eventually. In the absence of war, however, what motivating factor is going to push us to venture father out into the stars?
War, in general, is a great spur to technological innovation. I want to discuss this more broadly in response to those who say we lack the ability to realistically explore beyond our solar system. From 1914 to 1945 flight technology advanced from fairly unreliable bi and tri-planes, to jet propulsion. (Germany had put jets into active combat by the end of the WWII.) In a span of about thirty years we had progressed from a kind of go-cart with wings to a deadly killing instrument that would henceforward be the dominant weapon of warfare. In 1947 we broke the sound barrier. In the 1950s, when technological advancement was again spurred on by conflict – in this case the Korean War – test pilots were being killed at the rate of one per week. This mounting casualty toll did not stop countries from building much faster airplanes. And some of our airplanes now go very fast indeed.
FA-18 Hornet breaking the sound barrier
Currently we don’t seem to have the stomach for this kind of risk as we pursue our goals of flying faster and further. In 1986, the space shuttle Challenger blew up after launch, and space flights were halted for almost three years. In 2003, the shuttle Columbia disintegrated during reentry, and afterwards space flights were halted for two years. But this does not mean we are not progressing. In terms of flight speed, the shuttles typically exceed velocities greater than mach 2 during reentry. The Lockheed Blackbird, a manned jet aircraft, routinely flies at mach 3 and lands under its own power. In 2004, Boeing’s X-43A, an unmanned experimental aircraft reached about mach 9.7!
We have undergone tremendous advances in mobility in the span of a few decades without even trying on a global, or even multi-national level to push the rate of technological progress. Certainly our latest research efforts, particularly in space flight, should be described as laissez-faire: they are nothing compared to what we undertook in the World War years, or during the Cold War. We may yet discover that there is no upper limit to the speed we can travel. Relativity tells us we can’t exceed the speed of light, but Einstein’s Theory of Special Relativity is inconsistent with certain parts of the branch of physics called Quantum Mechanics. This inconsistency lies at the limits of our understanding of science. We simply won’t know if we can go faster until we push the envelope.
It took us about seven lifetimes – that is, seven spans of sixty years, to get us from the carrack, that multi-masted sailing vessel used by the Spanish and Portuguese, to the internal combustion engine. No one can imagine the state of technology seven lifetimes from now - but given the rate of technological advancement in this last generation, I think it is safe to say that things could evolve rapidly. Will it be enough to get us to Alpha Centauri A?
Using current technology, going at the speed of our fastest space probe, a production-year 2010 spaceship could arrive at this nearest star system in about 18,000 years.
Clearly, we have a lot of work to do if we seriously plan to realize our goal of exploring and colonizing other regions of space. This is a project of a vastly different order from our near-goal of allowing humans to set foot on another planet. A mission to Mars is well within our current technological understanding and capacity, we only lack the will to carry it through. Our real challenge is to test ourselves once more by opening a new era of exploration into the uncharted and the unknown. In all likelihood, other advanced civilizations are already out there discovering new worlds. We can’t afford to be left in the dust.
A Review of the Best Habitable Planet Candidates
17 hours ago