Elon Musk: We need a seed of human civilization somewhere else to bring back civilization to Earth and shorten the next Dark Ages.
“If you know that there's likely to be, we don't know, but there's likely to be another Dark Ages, which it seems, my guess is there probably will be at some point. I'm not predicting that we're about to enter a Dark Ages, but that there's some probability that we will, particularly if there's a Third World War.
Then we want to make sure that there's enough of us, of a seed of human civilization somewhere else to bring civilization back and perhaps shorten the length of the Dark Ages.
I think that's why it's important to get a self-sustaining base, ideally on Mars, because Mars is far enough away from Earth that a war on Earth, the Mars base might survive. It's more likely to survive than a moon base. But I think a moon base and a Mars base, that could perhaps help regenerate life back here on Earth, would be really important. And to get that done before a possible World War III.
You know, last century we had two massive world wars, three if you count the Cold War. I think it's unlikely that we will never have another world war again. It just could be radioactive rubble.”
Source: Elon Musk at SXSW 2018, Austin, Texas, March 11, 2018.