Proxima Centauri b Proxima Centauri b Proxima Centauri b (also called Proxima b or Alpha Centauri Cb) is an exoplanet orbiting in the habitable zone of the red dwarf star Proxima Centauri, which is the closest star to the Sun and part of a triple star system. It is located about 4.2 light-years (1.3 parsecs, 40 trillion km, or 25 trillion miles) from Earth in the constellation of Centaurus, making it the closest known exoplanet to the Solar System. Proxima Centauri b orbits the star at a distance of roughly with an orbital period of approximately 11.2 Earth days, and has an estimated
Long-distance running – all-weather tracks, roads and natural terrain, respectively. Typical long-distance track races range from 3000 metres to 10,000 metres (6.2 miles), cross country races usually cover 5 to 12 km (3 to 7½ miles), while road races can be significantly longer, reaching 100 kilometres (60 miles) and beyond. In collegiate cross country races in the United States, men race 8000 or 10000 meters, depending on their division, whereas women race 6000 meters . The Summer Olympics features three long-distance running events: the 5000 metres, 10,000 metres and marathon (42.195 kilometres, or 26 miles and 385 yards). Since the late 1980s,