Nature has shown us time and again that only species that adapt really fast to changes in their surroundings and calamities or the ones that prepare for it beforehand are the ones that survive.
Elon Musk might sound crazy when he talks about the colonisation of other planets in his interview with Aeon Magazine, but it’s the only option we’ve got: explore space and conquer other planets, until finally we have crawled out of this solar system and spread our seeds throughout the galaxy.
If you haven’t read the interview yet, I highly recommend you to read it now.
99.999% of all life that has ever existed on Earth has been wiped out by natural calamities, climate change and the occasional asteroid. It will not be long before a similar asteroid is on a collision course with Earth, again. We might not be prepared for what happens next, despite what was shown in Armageddon. We are completely at the mercy of probability, when it comes to asteroids and other killer occurences out in space, like solar flares and storms.
For all we know now, Earth is the only planet that has life (and intelligent life) on it. We may be a random occurence, a mistake, a glitch in the matrix, to put it subtly. We do not know yet if life exists beyond our planet. We have yet to cross the Moon when it comes to transporting humans into space. Most of the rockets that we plan to launch blow up. The last Moon landing was done about 40 years ago. But I really do dream of a tomorrow where humans have spread all over the Milky Way Galaxy, as in the Foundation Series by Isaac Asimov.
Self-preservation is the only motive behind Elon’s plan: self-preservation of the whole human race. He doesn’t dream of exploiting the mineral riches of other worlds, he just wants humanity to survive, no matter what happens. Of course, not everybody can and will go out to another planet all alone to set up a base. But over time, we would have enough people on enough planets that even a major disaster like the KT Event would not affect the whole human population of the Solar System much.
We humans are a peculiar bunch. We have a societal structure, developed over millions of years that is constantly changing. We have developed language, arts, culture, written words and books and formed a huge “networked” civilisation running on coal and silicon. I’m not implying humans are the pinnacle of evolution, we are merely a small part of what life on Earth is about. We are just a bunch of atoms that became sentient, developed curiosity and started learning about the atoms themselves. We were born from the cores of dying stars, and as we progress towards interstellar travel, we are moving closer to where we were born: the nuclear foundries of dead giants. That is all the more reason we need to get up and spread the seeds of our species far and wide.