Elon Musk says

“You need to live in a dome initially, but over time you could terraform Mars to look like Earth and eventually walk around outside without anything on... So it's a fixer-upper of a planet.”

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“Humanity has been small. That’s not true anymore. The Earth is no longer big. Humanity is big. Earth seems big to us, but it’s finite.”

“We need unifiers, not vilifiers. When you look out at the planet, there are no borders. There’s nothing. It’s one planet and we share it and it’s fragile.”

“We need to take all heavy industry, all polluting industry, and move it into space. And keep Earth as this beautiful gem of a planet that it is.”