Proxima Centauri b is a rocky exoplanet, meaning it’s a planet orbiting a star outside our solar system and is thought to be composed primarily of rock and metal. Orbiting the red dwarf star Proxima Centauri, it holds the title of the closest exoplanet to Earth ever discovered. Proxima b is estimated to be slightly larger than Earth, with a mass of about 1.27 times our planet’s. However, unlike Earth, it orbits its star at a very close distance, completing a full revolution in just 11.18 days. This proximity places Proxima b within the star’s habitable zone, the region where liquid water could potentially exist on a planet’s surface.