"I am the most extreme object in the universe. Nothing that enters me ever returns. Not even light escapes my grasp. I am invisible yet I bend space around me. What am I?"

Answer: A Black Hole. A black hole forms when a massive star collapses under its own gravity. Its gravitational pull is so strong that the escape velocity exceeds the speed of light — making even light unable to escape. They are invisible but detectable by their effects on surrounding matter.