Proxima Centauri b is the exoplanet closest to Earth, found 4.2 light-years away, orbiting the red dwarf Proxima Centauri within its habitable zone, where liquid water could exist. It is slightly more massive than Earth and completes an orbit every 11.2 days. While its atmosphere and surface conditions are unknown, the planet is considered a prime candidate for future interstellar robotic or crewed missions due to its proximity and potential habitability. | Wikinzie