Elon Musk wants to colonize Mars. In fact, the billionaire says it could happen within four years. He also says we could be living in a self-sustaining city on the red planet in the next 20 years. About This Article Elon Musk wants to colonize Mars.

And Musk's focus on Mars as the next destination for humanity after low Earth orbit should come as no surprise; the billionaire has long had the Red Planet in his sights. In a December X post, for example, he dismissed the moon as "a distraction," saying that "we're going straight to Mars."