Q: Why was it so hard to take a picture of a black hole? What are we even looking at?
The picture that you’ve already seen is of M87*, the supermassive black hole (SMB) in the middle of the galaxy M87. Our home galaxy’s supermassive black hole, Sagittarius A*, has the mass of around 4.1 million Suns, which is pretty massive. It turns out that black holes have an innermost stable orbit, that’s 3 times the Schwarzchild radius (3 times the black hole’s radius). So when you see a stream of hot gas beside a black hole, it might actually be behind it. The new black hole picture isn’t really a discovery, but it is a stunning accomplishment.