Proxima Centauri b orbits the nearest star to our Sun, a red dwarf M-type just 4 light-years away. With a radius of 1.0 × Earth, it circles every 11.2 days at 0.05 AU, squarely in the habitable zone where liquid water could exist given a suitable atmosphere. Tidal locking likely creates perpetual day and night sides, yet atmospheric circulation could moderate extremes. As the closest potentially habitable world, it anchors the eternal Galactic Codex and fuels timeless speculation about life in our immediate cosmic backyard.
