Elon Musk, the entrepreneur behind the Tesla Motors electric car company and countless other ventures, wants to expand his presence in space. Musk plans to extend his SpaceX company, a company that hopes to put private citizens in space, to build a colony on Mars. The colony would house 80,000 inhabitants (see update below), and Musk hopes that he will be able to transport visitors to the colony for $500,000 a person.
Transports of visitors would be initially be limited to 10 people or less, and they would ride to the Red Planet on reusable rockets. The colony itself would be covered with transparent domes, which can be pressurized and possibly support the growth of crops.
If this all sounds like science fiction, it's because it's not far off from it at this point. The total project is expected to cost roughly $36 billion, and Musk is a long ways off from breaking ground on it. The entrepreneur hopes to put people on Mars within the next 12 to 15 years, but for now, a Mars colony is still in the realm of creative science fiction writers.
Update: Musk has clarified that he intends for 80,000 to immigrate to Mars per year, not in total.