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.