Why does Elon Musk believe he can save the world by colonizing Mars? When PayPal was bought for $1.5 billion, Elon Musk and other company founders made huge personal fortunes. Musk used his to start the rocket company, SpaceX. He also began talking about very big plans for the future of humanity. He wanted humans to become ‘a multi-planetary species’ and said he was accumulating resources to 'extend the light of consciousness to the stars’. Soon he was talking about humans moving permanently to Mars. Future-of-humanity questions used to belong to religion and philosophy. Under ‘Muskism’ they belong more to engineering and entrepreneurship. Jill Lepore traces the history of Silicon Valley's fascination with existential catastrophism. In the second of five programs, strap in to head to Mars.