Killers of the Cosmos

It was a single rock that wiped out the dinosaurs -- does the same fate await humans?

A spy satellite chances on a threat from deep space. When a massive star dies, it can direct a blast of radiation that would obliterate life on Earth.

A collision of space debris could set off a chain reaction that leads to a global communication meltdown.

Aliens could be lethal killers who want to invade and plunder our world; a team of experts investigate extra-terrestrial beings and their threat to human life.

There are probably millions of black holes in the galaxy. Worse still, some are rogue, speeding through space with the potential to destroy Earth.

Experts discuss the many possible ways that could spark the beginning of the end for the universe, including when and why it would happen.