Humanity is on the verge of a new frontier—colonizing the solar system. But what’s actually stopping us? From the challenges ...

Doing so would offer more than just a satisfying answer: it could also open a new window on the history of the inner solar system, and perhaps point to the source of life’s building blocks on Earth.

Understanding how the habitability of our solar system's inner planets—Mercury, Venus, Earth and Mars—would change had there been a super-Earth opposite Mars can help guide astrobiologists ...