Astronomers think that they have found some strange objects out in space. They have called them BLACK HOLES.
A Black Hole is a sort of invisible whirlpool that sucks in everything around it - I mean everything, even light.
The gravitational field of a black hole is rather like that shown in the diagram.
Once you have slipped into a Black Hole you can never get out.
Once you have been sucked into a Black Hole you can never get out again. It’s all to do with ESCAPE VELOCITY.
The pull of gravity of a Black Hole is so huge that its escape velocity is as big as the speed of light. That’s why it’s black, light that goes in can't get out.
Since nothing can go faster than light – or even reach the speed of light if a spaceship got pulled into a Black Hole it would be trapped there forever.
A black hole is usually the result of the collapse of a star that had a mass of between 5 and 100 times that of our Sun.
At the end of its life the star contracts so that all its mass is enclosed in a very small volume so that the gravitational pull near its surface would be enormous.