Elon Musk, the CEO and founder of Tesla Motors and SpaceX, has recently told the media that he believes humanity could reach Mars in 10-12 years.

Musk spoke with Kelly Evans on CNBC's "Closing Bell" on Tuesday, after the network named SpaceX and Musk at the top of their Disrupter 50 list - a list of "companies that are revolutionizing and disrupting" their respective sectors.

During this interview, Julia Boorstin of the Disruptor 50 initiative asked Musk about the feasibility of putting people on Mars. Musk was surprisingly quick to answer.

"I'm hopeful that the first people could be taken to mars in 10, 12 years. It think it is certainly possible for that to occur," he told CNBC.

However, Musk didn't stop there. The main goal of humanity, he said, is for man to have a self-sustaining city on Mars.

That is what matters in the long run, he reiterated, adding that humanity "will either be a multi-planet species... or a single planet species until some eventual extinction event."

That is a tall order, even for the founder of a company dedicated to space travel. Currently, SpaceX is mostly serving as a delivery service, transporting valuable cargo to the International Space Station (ISS). The company's next major and immediate goal is to transport people. However, compared to ISS transport, Mars colonization is a very different animal.

But planetary scientist Philip Metzger of the NASA Kennedy Space Center says that is isn't a completely insane dream. "Living off the land" on the Moon or Mars is quite possible, he told Reuters.

"No miracle inventions are required. No new physics. Just straightforward engineering and a modest budget for the development cost," Metzger said. "My personal opinion is that I am optimistic. His organization has demonstrated efficiency... he's doing all the right things."

Still, there are some doubts about putting a man on Mars at all. A report from the US National Research Council concluded earlier this month that if NASA continues to function at its current level, the United States will never be able to reach the Red Planet. Doubters worry that if NASA can't even reach Mars, what makes Musk think a private company can?

The committee also concluded that the purely practical and immediate economic benefits of human spaceflight do not justify its exorbitant costs. However, they also established that the grand human achievement could make it all worth the effort.

Dolly Singh, a former employee of SpaceX, told Reuters that Musk's goal is "clearly not a 'reasonable' thing to undertake." But, she says - quoting George Bernard Shaw's Man and Superman - the unreasonable man adapts the world to himself. "Therefore all progress depends on the unreasonable man."