The Milky Way is a large galaxy with 400 billion stars, but the relationships between these stars can be chaotic. For example, the closest star to the Solar System, Proxima Centauri, is currently 4.2 light-years away. However, both the Sun and Proxima Centauri are constantly moving within the Milky Way, and other stars may come close to the Sun in the future, even entering the Solar System's Oort Cloud and posing a threat to Earth.
Barnard's Star is one such star. It is a red dwarf located in the constellation of Ophiuchus and is currently only 6 light-years away from the Sun. Astronomers have predicted since its discovery in 1916 that it may enter the Solar System and even collide with the Sun. Unlike other stars near the Sun, Barnard's Star has been parallel to the Solar System for a long time, allowing it sufficient time to approach the Sun. Its mass is only 0.17 times that of the Sun, and its radius is only one-fifth that of the Sun.
However, its internal fusion reaction is milder, resulting in a much slower consumption of hydrogen compared to the Sun. Therefore, the lifespan of red dwarfs, like Barnard's Star, is generally several hundred billion years, while yellow dwarfs like the Sun only live for about 10 billion years. While Barnard's Star is approaching the Solar System due to the Sun's revolution around the center of the Milky Way at a speed of 220 kilometers per second, astronomers do not believe it will collide with the Sun. The difficulty of two stars in the universe colliding precisely is comparable to that of two specific dust particles colliding on Earth.
In about 10,000 years, Barnard's Star is expected to reach a distance of only 3 light-years from the Solar System and replace Proxima Centauri as the closest star to the Sun. Whether it will continue to approach the Solar System at that time is uncertain, as anything could happen over the next ten thousand years. However, Barnard's Star is not alone; it also carries an exoplanet named Barnard b. This red dwarf has its own planets, similar to the existence of Proxima Centauri b and Proxima Centauri c near Proxima Centauri.
Preliminary analysis suggests that Barnard b is a rocky-metallic planet with a mass three times that of Earth. Although it is not located within the habitable zone of Barnard's Star, it may provide humanity with valuable metallic resources from an exoplanetary mine in the future. As the third closest star to the Sun, Barnard's Star has been selected in the past for programs searching for extraterrestrial civilizations. As early as 1960, astronomers used radio telescopes to detect signals in the direction of Barnard's Star but received no unnatural electromagnetic waves. Subsequent attempts to search for extraterrestrial civilizations also focused on Barnard's Star but yielded no results either.
Although astronomers no longer have much hope of discovering extraterrestrial civilizations near the Solar System, if human civilization still exists ten thousand years from now, they may launch probes or even personally visit the planet Barnard b. Even if there are no aliens there, it can provide valuable resources.