Now, I am not talking here about the petty little threats to our survival - pollution, global warming, nuclear war, and the like. I am talking about the threat of our extinction at the hands of something completely out of our control - the vast, dangerous, uncaring nature of the universe itself. This year is the International Year of Astronomy, and that, as well as the fortieth anniversary of the moon landing, has sparked some mild interest again in the potential of space travel, as well as discussion of its worth to humanity. Why, many people may ask, should we spend so much time, money, and resources on looking and traveling out into space when we could use that time, money, and resources to fix problems here on Earth? It is a legitimate question that does not have an easy answer. I hope that this post will show why it is also not a question with an all-or-nothing answer. I believe that we need to have a balance of time and resources spent on fixing the problems of the present and keeping an eye on the future as well. And space travel must play a part in the future of humanity.
Stephen Hawking made a very important observation in his famous lecture on Life in the Universe, one that gives a potential answer to the Fermi Paradox: the contradiction between the high estimates of the probability of the existence of intelligent extraterrestrial life and the lack of actual evidence for such life. When the universe is looked at mathematically through hypotheses such as the Drake equation, it seems statistically unlikely that we are the only intelligent beings in the universe. However, no contact with another intelligent species has ever been made. There are obviously many possible reasons for this - I will not list them here - but the one that Hawking proposed is one that has direct and serious implications for the survival of the human race. He states that one of the reasons why the universe may not be teeming with evidence of extraterrestrial intelligence is because most planets on which any life evolved may have had that evolutionary process interrupted before it could get to a complex enough state to develop intelligence - by asteroid impacts.
It is roughly estimated that asteroid collisions with Earth-sized planets occur every one to twenty million years. The last major impact to our own planet, the asteroid impact that is thought to have caused the extinction of the dinosaurs, occurred seventy million years ago. Even by statistical standards, and accounting for the fact that Earth is protected from more frequent collisions by the massive gravity well of Jupiter, we are long overdue for another one. And while life would still survive in the event of a major collision - bacterial and microbial life would almost certainly survive, and anything up to small mammals also, depending on the size of the collision - large and complex life-forms, humans included, would almost certainly be completely wiped out. It took 70 million years for the small mammals that survived the last great collision to evolve into intelligent human beings, and the evolution of actual intelligence has only occurred within the last several million years. So, even if microbial life, or multi-cellular life, or even recognizable speciated life has occurred on other planets in the Universe, which is quite likely, it seems equally likely that asteroid impacts and other extra-planetary disasters may have hindered continuous evolution to the point that intelligence is vastly more rare and difficult to achieve than we previously thought.
So what does this have to do with colonizing Mars? Simple. If we distribute the human race among the other planets in our solar system - even just sending a small, sustainable colony to one other planet - then we completely remove the risk of having our entire species wiped out by a single catastrophic global event, such as an asteroid impact. And why do I think this is important? The simple answer is obviously that no one wants to see the entire human race wiped out so easily by something completely beyond our ability to control. But more importantly, consider the possibility, as outlined above, that the evolution of intelligent life in the universe is vastly more rare than previously statistically calculated. Consider the very frightening and awe-inspiring possibility that we may be the only intelligent beings currently in existence. In the entire Universe. Now consider the fact that the Universe does not - not for one second - care about that fact. It is through extreme luck and marvelous circumstances that we have been able to survive and that we are aware of that fact. And we have within our power to thwart chance and to find some way to survive despite the statistical odds stacked against us. No other species on this planet has that ability. And we owe it to ourselves, our future generations, and maybe even the Universe, to do everything in our power to preserve the human race. Otherwise, we risk allowing something extremely unique and rare to be destroyed, maybe never to come again.
And though sending people to Mars may not be possible yet, with our current technological and social limitations, it is a goal worth working towards. Because the next asteroid may not come for another seventy million years, but it could come within the next thousand years, or the next hundred. And it will probably take at least that long to get people to realize the importance of finding ways to preserve and protect all of humanity along with improving it. We have the technology and the foresight to start working on this now - there is no reason to wait.
And you don't have to take my word for it, but can you really justify ignoring Stephen Hawking?
