Earth has been considered the only planet that offers environments suitable to sustain human life. This is why any other planet has never been considered for migrating humans. This is why Elon Musk wants us to consider Mars as a possible planet to shift to.
Well, if we have been living on Earth for so long what has changed now. Earth saw five mass extinctions, wiping out large portions of human population. And Elon Musk believes that the next apocalypse may prove too much for us to survive.
Elon Musk thinks that we need to go off Earth and consider living on other planets instead. Mars is typically one of the planets that he is most interested in for mass human migration from Earth. He says that we may have the technology to deflect the next big rock heading our way but if something overwhelmingly big happens, we may not be equipped to handle that.
Elon Musk compared Earth’s vulnerability with that of a hard disk which crashes on a regular basis. And if we have stored a very important excel document on it despite of knowing that this hard disk can crash any time, we are risking our file. The same applies for risking our lives by not exploring other options to vacate earth in case there arises a need.
His plans for Mars are also unprecedented. Earlier Mars colonization planners including the Chinese have shown no intention to send more than handful of people. Elon Musk on the other hand is planning to send 1 million people there. And the explanation that Elon Musk offers for planning to send so many people is to have enough genetic diversity on the planet to tackle the unique challenges that its environment offers. Elon Musk is about to unveil a rocket at the end of 2015 which will be capable of carrying 100 people to Mars. He has named this new rocket capsule Red Dragon.