I lot of people don’t know this but astronomers have never photographed a black hole; any picture that you and I have seen is merely an illustration. The reason scientists know that black holes exist is they were tracking a group of small stars and noticed that something was pulling gases off of them. The gases spiraled into something they couldn’t’ see and then disappeared. At the place where the gases disappeared they noticed (through the use of orbiting telescopes) extreme heat and radiation; but then everything went black again. The radiation was detected by the scientist: Steven Hawking. Scientists dubbed this spot in space a “black hole.” They are also able to discover where black holes exist by seeing areas in space where there were no stars. As you know, when you get outside of the city about all you see are stars and they all seem to be so close they’re touching. Through using their powerful scopes they identify unusual spaces that are empty. They then more closely monitor these areas for radiation.
One good way of visualizing this is to think about Saturn floating next to a large black hole. If this happened the rings around Saturn would begin to be pulled like taffy towards a spot in space you couldn’t see. As this happened you’d see an extreme hot spot and then a burst of radiation; then you’d know where the opening to the black hole is. Then it would turn completely black again as if nothing had happened; of course Saturn wouldn’t look as interesting anymore!
While scientists went searching for other black holes they came across a super large one that was grabbing gases over a huge part of space. Not being all that creative they came up with the name: “Super Massive Black Hole.” They’ve got to regret that one! The first one they found was at the center of our Milky Way Galaxy. This galaxy has 400 billion stars for the black hole to feed on.
Scientists have wondered what would happen if a spacecraft flew into a black hole. Some of them think a black hole could be a portal (a.k.a. worm hole) to other parts of space or even time; of course many movie producers have used this idea in their SciFi films.