Musk said in an interview this week with Fox News host Jesse Watters that his focus on Mars has to do with ensuring humanity's longterm survival.

Elon Musk is taking the long view. The billionaire SpaceX founder has long said that humanity needs to expand its footprint out into the solar system — specifically to Mars, which is the most suitable and reachable target — so that we won't go extinct if something bad should happen to Earth.