Elon Musk is a South African-born U.S. engineer who founded of Tesla Motors, SpaceX and PayPal. He decided when he was in school that there were three important problems he wanted to pursue in life – the internet, clean energy and space exploration, particularly making life multi-planetary.

He appeared on “The Daily Show” Tuesday evening (April 10), where he spoke with host Jon Stewart about a rocket he invented and the challenges of colonizing Mars. Stewart points out that the four entities that have launched rockets into orbit are the U.S., China, Russia … and Elon Musk.

“People often wonder how I went from internet payments to rockets … I didn’t expect that I would actually be doing them. The advent of the internet and particularly the sale of PayPal gave me the capital to start a rocket company and a car company,” says Musk.

“The ultimate goal of SpaceX is to develop the technology necessary to make life multi-planetary. To enable a self-sustaining civilization on Mars,” says Musk. “The moon’s a small rock, but it’s got no atmosphere, limited natural resources … it’s essentially impossible for us to travel to other star systems … the next logical step is to make life multi-planetary. That will create a forcing function for improving space transportation technology.”

And he says the reason they need to keep working towards these goals are two-fold.

“To ensure the continued existence of humanity … the other reason is there have to be things that are exciting and inspiring,” says Musk.

It’s a fascinating interview and definitely worth watching both videos.