EVEN A ROCKET TRAVELLING AT THE SPEED OF LIGHT COULDN’T ESCAPE FROM A BLACK HOLE

As objects become more massive and more dense, it becomes increasingly hard to escape their gravitational pull. For a rocket to escape the gravity of Earth, it must travel at a speed of 11.2 kilometres (6.9 miles) per second. From the surface of the Sun that speed rises to 618 kilometres (1,005 miles) per second, and from a dense white dwarf star like Sirius B, the same rocket would need to travel at 5,200 kilometres (3,231 miles) per second in order to escape. Within the grip of a black hole, even a rocket travelling at the breakneck speed of light, or 299,792 kilometres (186,282 miles) per second, would be unable to free itself from the immense gravitational pull.