For years, popular culture has treated a human settlement on Mars as an almost inevitable next chapter, a matter of engineering and willpower rather than fundamental limits. Astrophysicist Neil ...

The New York Times reported Elon Musk had volunteered his sperm as part of SpaceX's plans to build a city on the red planet.

A lunar colony would be far preferable to one on Mars. Its foundation is within the ambit of modern technology, and it could be rapidly serviced from Earth. The moon has many valuable resources, ...