Season 1, Episode 4

1. Killer Rocks

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

2. Dark Star

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

3. Death Ray

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.

4. Cosmic Scrap

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

5. Little Green Men

If they exist, aliens could be killers who want to invade and plunder Earth, threatening human life.

6. Big Sleep

Everything comes to an end, even a universe. So, how will it all end? Will gravity make it collapse, or will it expand forever?

1. Killer Rocks

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

2. Dark Star

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

3. Death Ray

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.

4. Cosmic Scrap

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

5. Little Green Men

If they exist, aliens could be killers who want to invade and plunder Earth, threatening human life.

6. Big Sleep

Everything comes to an end, even a universe. So, how will it all end? Will gravity make it collapse, or will it expand forever?