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Black holes - What is the name of our universe? - What other planets are in our universe? What is black hole? • Black hole is a very powerful gravitational force that can grab the tiniest or the largest thing. • A black hole is a region in which the gravitational field is way more powerful than anything else it is near • Absolutely nothing can escape a black hole, not even light can escape from their gravitational force. • If you were to ask an astronomer this question, they are most likely to say that a black hole must be one of the most strangest objects ever. They are almost like an incredibly strong vacuum cleaner without the noise - not only would the crumbs from under your bed be unable to escape, but anything that happens to travel past would have a hard job trying to wriggle free from its clutches, too. Where are black holes • Black holes are in between each of the galaxies, there are millions to billions black holes in the space. • Black holes can even grab nearby stars. It is because of black holes the galaxies are made. Black hole’s gravitational force This is the image of the black hole’s gravitational force. The black hole’s gravitational force is extremely powerful. There are 3 different types of black hole How do Black Holes Form? • When a large star runs out of fuel it can no longer support its heavy weight. The pressure from the star's massive layers of hydrogen press down forcing the star to get smaller and smaller and smaller. Eventually the star will get even smaller than an atom. Imagine that for a moment, an entire star squashed up into less space than a tiny atom. How can something get smaller but retain the same amount of mass? • It is really quite simple. If you take a sponge the size of a soda can, you can easily squish it in your hands until it is completely covered. But here is the interesting part. If you make something smaller by squishing it, its gravity becomes much stronger. Imagine then, if you squish a star into the size of an atom how powerful its gravity would become. Anatomy of a Black Hole • Black holes are made up of 3 main parts. The very outer layer of a black hole is called the Outer Event Horizon. Within the Outer Event Horizon you would still be able to escape from a black hole's gravity because the gravity is not as strong here. The middle layer of a black hole is called the Inner Event Horizon. If you didn't escape the black hole's gravity before you entered the Inner Event Horizon, then you have missed your chance to escape. The gravity in this layer is much stronger and does not let go of objects it captures. At this point you would begin to fall towards the center of the black hole. The center of a black hole is called the Singularity. This is simply a big word that means squashed up star. The Singularity is where the black hole's gravity is the strongest. How are Black Holes Formed? • A stellar-mass black hole is made when a gigantic star reaches a grand old age, causing it to explode in a very bright burst of light - so luminous that it can outshine a galaxy! Astronomers call this explosion a supernova and they happen when an old star has finished burning all of its fuel. There is often material left over from a supernova and scientists call this a stellar remnant which they think then collapses in on itself transforming into a very compact object. And there we have it - a stellar-mass black hole is made! How can you fall into a black hole? • Think of the Earth. When you are in outer space you can float around. If you get too close to the Earth you will be pulled in by its gravity. On the Earth, you could leave again in a rocket ship. However, if you fall into a black hole, there would be no way to get out because the gravity is so powerful. • The second type of black hole, the supermassive black hole, is the same as 100 million Suns all squashed into one place. However, unlike its smaller cousin, astronomers are not entirely sure of how they are made - one thing they are positive of though is that there is one right in the middle of our galaxy, the Milky Way, and there could be more in the center of other galaxies, too