On March 29th, 2001 (March 5th, 2001 in the lunar calendar), human beings discovered a black hole on the edge of the Milky Way galaxy for the first time. On March 29th, 2001, a research team composed of scientists from many countries observed a black hole at the edge of the Milky Way galaxy with a multi-lens telescope located in Arizona, USA. This is the first time that humans have discovered a black hole at the edge of the Milky Way galaxy. The black holes observed in the past are all located in the center of major galaxies. Compared with ordinary black holes, although this black hole is relatively small, its mass is at least 6 solar masses, 6,000 light-years away from the earth, and it is located in the halo region covering the Milky Way galaxy. Because of the extreme gravity of black holes, even light is sucked in. Therefore, scientists only conclude the existence of black holes from other evidence. Near this newly discovered little black hole, there is a star revolving around the black hole with a period of 4 hours. Scientists found that this star was constantly losing due to the gravity of the black hole, and these substances were sucked into the black hole in a spiral trajectory, thus discovering the black hole. The concept of black hole was put forward scientifically about a century ago. How to prove the real existence of black holes by observation has always been one of the most challenging topics in modern astrophysics. Discovered a star with a speed of 2.6 million kilometers per hour, suspected black hole is swallowing up