It's obvious that for our survival we need to become interplanetary species. It's only matter of time (doesn't matter if it' 200 years or 2000 years, it will happen eventually) until meteor (or other similar event) will hit earth and only primitive life will probably survive. There is a lot more of random natural extinction events that could eliminate human beings (meteors, super viruses etc.). Additionally we create our own problems that could threaten our existence (global warming) and how many more that we don't even know (our knowledge is limited) we created?
Getting on Mars is our best bet for now, as human race. If we can colonize Mars, this will double our chances of survival.
