Black Holes are super dense regions of space. They have such immense gravity that anything close by is sucked in, never to escape. Even LIGHT! That's why we call the BLACK HOLES. Some black holes are small. Some are HUGE! There are stellar black holes, about the size of a dozen of our suns. Then there are SUPERMASSIVE black holes, that are the size of MILLIONS and MILLIONS of our suns! Scientists think there are supermassive black holes in the center of each galaxy. The supermassive black hole in the center of our Milky Way galaxy is called Sagittarius A. Recently, the Event Horizon Telescope was able to image the supermassive black hole in the center of the distant galaxy Messier 87. This black hole is known as M87, and was the first black hole ever to be imaged using the giant radio telescope EHT. In this video, we talk about how Black Holes are formed and how we can detect them using various methods.