The billionaire founder of companies including private space firm SpaceX hopes to one day take private citizens to the red planet, with the hope they might live there.
And a journey will be eventually be relatively cheap, he says, though it depends in part on how many people actually want to go.
Asked on Twitter about how much the journey will eventually cost, he said that it would be cheap enough that many homeowners could easily relocate to live on Mars instead.
"Very dependent on volume, but I’m confident moving to Mars (return ticket is free) will one day cost less than $500k & maybe even below $100k," he wrote. "Low enough that most people in advanced economies could sell their home on Earth & move to Mars if they want."
Mr Musk hopes that space travellers will eventually make their journey on SpaceX's starship, a new craft that is going through the testing process.
A number of Twitter users asked the SpaceX boss what the public could do to support its development, apparently in the hope of being allowed to make trips to Mars as soon as possible.
"The goodwill of the public is critical to Starship’s success," he wrote in one post.
He was then asked how he would ensure the public stayed engaged with the project. He joked that there would probably be some RUDs – rapid unscheduled disassemblies, which is how SpaceX refers to the events other people might call an exposion – but that there would be plenty to get excited about.
"Just planning on keeping the public informed about progress & setbacks," he wrote about his plans. "Will be some RUDs along the way, but excitement is guaranteed!"