If the human race is to continue to survive as a species, colonization of space is essential. At this writing, our planet Earth holds approximately 7 billion inhabitants. As our lifespans as a whole continue to rise, it stands to reason that our world's population will likewise increase. In fact, at our current rate of growth, there will be 10 billion people living here by 2100. To put this into perspective, that is about double the amount of the world's population in 1990. Moreover, this is already taking into account premature deaths from all causes, such as conventional wars, pestilence, crime and accidents.
Of course this growth could be slowed down with some as-yet-unknown airborne virus that could wipe half of us out. Some suicidal lunatic could engage nuclear warfare as well. We could continue to destroy our atmosphere with man-made pollutants which would eventually make our planet uninhabitable. An undetected asteroid the size of Massachusetts could be headed on a collision course with Mother Earth as you read this. But we don't like to think about those things, do we? And indeed we have managed to dodge such disasters thus far. Yet this is all the more reason we need to expand into space, for some day, our luck may just run out. With a population that has the potential to double each century, we need to become as serious about this as we finally are beginning to be about cleaning up the environment.
Aside from our single moon, Mars is the closest body in space that carries the potential for human expansion. Venus is closer, but the surface temperature of some 900 degrees Fahrenheit is a bit on the toasty side. This isn't to say that we could walk around outside on Mars without protection, either. It's cold there. The surface can get as warm as 80 degrees, but the surrounding air almost never gets above the freezing point of water. The Martian poles make Antarctica look tropical with temperatures that can reach 225 degrees below zero. The air is very thin and made up mostly of carbon dioxide. Because of the thin atmosphere, solar radiation would make our Coppertone sunscreen useless. Yet colonies with Earth-like air could still be constructed under strong plexiglass, and individuals could venture outside of these bubbles provided they were equipped with oxygen and protective suits such as those worn by astronauts.
Traces of water have been found on Mars, but obviously, settlers would have to produce their own by mixing hydrogen with oxygen and recycling it. Greenhouses with artificial environments could grow vegetation. As for protein-enriched foods, it could either be manufactured in a lab or shipped from Earth. The bottom line? It would be possible to build colonies not only on the moon and on orbiting space stations, but also on Mars. Over a long period of time, it has even been suggested that terraforming could become reality on a planet such as Mars. Literally, we would change the planet's properties to those of Earth. However, at the present time, the technology and resources to perform such a feat are very limited. But future generations of people living in those bubbles could eventually conquer the necessary steps.
In centuries past, humans embarked on uncertain journeys thousands of miles across our oceans in search of new lands to settle. Our survival depends on expanding our civilization just as those who preceded us. Perhaps best of all, there would be a significant difference. In the past, expansion and colonization meant aggressively taking land from natives who already lived there. Suffice to say, we wouldn't have to worry about that on Mars. To all of the science fiction writers of decades past who concocted a vast array of interesting aliens hailing from the Red Planet to entertain your readers, we must apologize.
There's nobody there to conquer. As Ray Bradbury once stated, WE would become the Martians.