For the first time, we can see a picture of the black hole at the heart of our Milky Way galaxy (银河系). On May 12, an international research team showed the picture. More than 300 researchers from 80 institutes (机构) around the world worked together. They used radio telescopes (无线电天文望远镜) around the world to take the picture. The black hole － called Sagittarius A*－ is 27,000 light-years away from Earth, and 4 million times bigger than the sun. In 2019, scientists got the first picture of a black hole in the center of a galaxy known as M87. Now they can study the differences between these two black holes.