BLACK HOLE

Black holes are termed as monsters of universe. Their gravitational pull is so strong that nothing, not even light 

( electromagnetic radiation ) can escape from it. This makes it impossible for humans to see them. A black hole

is formed when a giant star collapses due to its own gravity when it had used all its hydrogen fuel and shrinks 

to become a much smaller entity. this causes a lot of matter to be packed in a small space causing an immense 

increase in gravitational pull.