Black holes

Tanno and Iguda’s postcard from the centre of galaxy M87 showed the first time we’ve ever taken an image of a black hole. Astronomers believe most galaxies have a supermassive black hole at the centre.

This photo shows how the Event Horizon Telescope team were able to zoom in and zoom in to finally see the black hole.

Image Credit: NASA/JPL-Caltech/IPAC/EHT Collaboration

This picture shows galaxy NGC1097, which is about 50 million light years away. It looks like it has an eye at the centre, because its black hole has dragged in millions of stars really close to it.

New stars are being formed in the spiral arms. The fuzzy blue spot on the left is another galaxy, but we aren’t sure if it forced a hole in the spiral arms, or just happens to be sitting in a good spot for us to see it.

Image Credit: NASA/JPL-Caltech


Lost in Space??? Learn about how we measure the huge distances in space. Click here: What is a light-year?


What is a black hole?

Some objects in space are very dense. This means that they have a huge amount of matter. Matter is basically any kind of stuff you could touch – so NOT the force between two magnets, but the actual magnets themselves are made from matter. All matter causes gravitational forces, usually too small for us to feel. So the force you feel between two magnets is not their gravity – that’s too weak – it’s their magnetic force.

This picture shows the superstrong gravity from black hole Cygnus X-1 dragging matter from its neighbour, a blue supergiant.
Image Credit: NASA/CXC/M.Weiss

Objects with a high enough density will create enough gravity so that anything too close to them will be sucked in and become stuck, unable to escape. That’s a black hole. Big black holes can be spotted by telescopes looking for X-rays. A lot of energy comes out of material the black hole sucks in, because that matter will start to move really fast. Often this energy comes to us as X-rays.

Activity

Scientists ask questions. Being curious is one of the most important things about being a scientist – we always want to find out why things happen. Scientists love to wonder “Hmm, what would happen if …?”

Black holes are really strange things. Write down five questions about black holes that you would like to know more about.

NASA has many webpages that try to explain all about black holes. Click on this link to go and read 10 questions and answers that they thought people might be interested in. Next to each of your questions, research what people know already and write a short summary about each answer.


You can go to the previous DeepSpace secret page by clicking below.

Distant Universe