At some point in the distant future, Earth will no longer be able to sustain life. The sun provides the heat and energy needed for life -- but it has a lifespan. As it gets closer to its death, the sun will enter its red giant phase and expand to approximately 100 times its current size. At that size, it would engulf Venus [source: Britannica]. Whether it will swell large enough to consume Earth is debatable. But even if it doesn't, the sun will boil away all water and heat the surface past livable conditions. So what are our options? Move to Mars?
Now that you're terrified, relax. At an estimated 4.6 to 5 billion years old, the sun is thought to be approximately halfway through its life. Scientists predict it won't begin to burn out (and expand) for another 3 billion years [source: Britannica]. In the meantime, our planet faces other uncertainties. With any number of catastrophes in the past, present and future such as the Ice Age, global warming or asteroid strikes, life on Earth is fragile. So maybe colonizing Mars isn't such a bad idea. Setting up a colony on Mars could potentially expand our reach into space, and give us an option for sustaining life.
Though it may sound like science fiction, a mission to Mars isn't that farfetched. We've sent several unmanned mission to Mars such as Mars Pathfinder, Viking, Mars Global Surveyor and the Phoenix Mars Lander [source: NASA]. But there are plenty of challenges involved before we could establish a permanent colony. Here are five hurdles we would need to conquer before colonizing Mars.
Even though it's the closest planet to Earth for sustaining life, Mars is currently uninhabitable by humans. Yes, it has an atmosphere, wind, clouds and days are similar in length to ours at 24 hour, 37 minutes. Mars even has seasonal changes too [source: Britannica].
But that's essentially where the comparisons stop. By all accounts, Mars is a geologically dead planet. While Mars has plenty of volcanoes and geological evidence that there was tectonic activity at some point in its history, that's not the case anymore. There is no air pressure to hold in water and Mars suffers from the lack of a magnetic field that would shield it from harmful solar winds [source: Fox]. Any effort to process Mars into a livable planet (i.e. terraform) would have to take all these factors into account.
Perhaps it would be possible to jumpstart the atmosphere by turning the carbon dioxide-rich air into oxygen much the way plants on Earth clean our air. But Mars still wouldn't have a magnetic field. Without a magnetic shield for protection, extreme waves of solar radiation strip away the Martian atmosphere, thus subjecting humans to lethal doses of radiation. Evidence suggests the polar ice caps have the remnants of a magnetic shield and are safe from the extreme solar radiation [source: Fox]. If nothing else, terraforming could be limited to those regions.
4. Cost of a trip to Mars
NASA can build a vehicle that would take astronauts to Mars. In fact, that's what the Orion project aimed to eventually accomplish before it was drastically cut back by U.S. President Barack Obama in early 2010 [source: NASA]. So if NASA isn't planning to go to Mars anytime soon, where does that leave us? It seems unfathomable that a trip to Mars would ever be cost-efficient. And by virtue of Obama's decision to cut the Constellation program in early 2010, it appears any venture would have to be privately funded. [source: Marcus].
Estimates by some experts have put the price tag for a Mars trip in the hundreds of billions of dollars [source: Tyson]. The exorbitant costs can be attributed to many factors but a large one lies in the need to send multiple vehicles for a return trip to Earth. For instance, one vehicle would contain nothing but fuel and supplies needed for re-entry. Of course, one radical idea is to forgo a return trip entirely. Instead of returning, travelers to Mars would get a one-way ticket to stay and colonize, with periodic reinforcements of people and supplies. One-way trips could cut costs considerably, perhaps as much as 10 times according to some experts [source: Tyson]. The time between supply runs would probably be two years as Mars' distance from Earth ranges between 34 million miles (55 million kilometers) at its closest to 249 million miles (401 million kilometers) when the two planets are at opposite ends of their orbits around the Sun [source: Cain].
3. What about our health?
A trip to Mars takes anywhere from seven months to a year to complete [source: Britannica]. That's up to a year cooped up on a small spacecraft. What would that do to the human psyche? Even men and woman as dedicated and expertly trained as astronauts would undoubtedly get on each other's nerves. That's only part of the problem though. Astronauts face a variety of health concerns when the body is subjected to zero gravity.
Prolonged exposure to zero gravity causes muscle deterioration and can weaken bones. Decreased bone density in particular would be something hard to overcome once the human body becomes subject to gravity again. A 40-year old human would essentially have the body of a geriatric once it reached Mars, making working in space suits and performing even menial tasks more than the body can handle [source: Joyner]. Other health concerns include a decrease in cardiovascular conditioning. Exercise would help. But even astronauts onboard the International Space Station for six months lost muscle and bone density and they exercised two hours daily [source: Joyner].
2. Would anyone want to go?
Mars isn't the most scenic place in the galaxy. With no bodies of water or vegetation, Mars is a gloomy place. Imagine living in the desert and it was -10 degrees Fahrenheit (-23 degrees Celsius) during the day [source: Britannica]. Would anyone actually want to live there? Would you?
To think life would be similar to what we know on Earth is science fiction at best. Would anyone want to be confined to a biodome or space station for life? Even if we were able to terraform Mars into an environment able to sustain plants and animals and we could walk around the planet without space suits and breathe the Martian air, it would always be cold and with just 40 percent the gravity of Earth, our bodies would experience dramatic bone loss and muscle atrophy [source: FactMonster].
Despite all of this, it's a safe bet the line to sign up for such a prospect would be quite long. Physicist Paul Davies has said that whenever he brings this up at lectures, people raise their hands to volunteer for the trip. Even Buzz Aldrin, the second man to walk on the moon, believes plenty of astronauts would volunteer to colonize Mars [source: Tyson].
1. Would colonizing Mars really save humankind?
If the goal is to move away from a dying planet Earth, how would we really survive if we are dependent on our home planet? It's hard to imagine a colony on Mars would ever be fully self-sufficient. But to have any chance of saving humankind, we would have to be completely independent.
Until the atmosphere is able to sustain life, all colonization would have to be done indoors. More likely than not, the manufactured elements of a space station or biodome would have to come from Earth. But even if we were able to build city-sized biodomes, Mars would still suffer the same fate as Earth once the sun enters its final stages of life. When the sun does consume all of its fuel, it will shrink to a carbon core known as a black. Even if Mars didn't succumb to the rapid increase in temperature during the Sun's red giant phase, nothing will survive without the sun [source: Britannica].
Then there are the questions of what type of species would we be two or three generations into colonization. If you believe in Charles Darwin's theory of natural selection, environmental factors will eventually change our traits and humans would eventually look different. In other words, we'd evolve into Martians [source: Britannica].
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- Encyclopedia Britannica. "Evolution of a Planetary Nebula." (Dec. 1, 2010)
- Encyclopedia Britannica. "Mars." (Dec. 1, 2010) http://www.britannica.com/EBchecked/topic/366330/Mars
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