What is a Black Hole?

A black hole is one of the strangest objects in space. It is an area in space where gravity is so strong that even light cannot escape from it. Since light cannot escape from a black hole, it appears black. Light can travel faster than anything we know of - at a speed of 186,000 miles (300,000 kilometers) per second. If light cannot escape from a black hole, nothing else that we know of can. A black hole is not really a hole and it is not empty. It is filled with a lot of material crammed into an extremely small space. This is what gives a black hole its super strong gravity. The term black hole is used because these objects look like black holes in space - since they put out no light.