1. Saturn's Moon Monsters

NASA discovers something strange on Saturn's biggest moon that might be aliens.

2. Aliens vs. Stalin at Area 51

A former Area 51 insider alleges that the Roswell UFO incident was a nefarious Soviet conspiracy.

3. The Black Hole Next Door

Astronomers investigate how much danger a black hole moving through the Milky Way poses to Earth.

5. Aliens in the Amazon

Experts ask if an encounter on the moon inspired Neil Armstrong's quest to find a legendary library.

6. Secrets of the Alien Signals

Experts wonder if an experiment to communicate with dolphins is a prelude to making alien contact.

7. Planet of the Metal Aliens

Experts investigate if a nearby exoplanet could be the home of an alien civilization.

8. Did Aliens Nuke Mars?

Experts investigate if an alien Armageddon transformed Mars into the wasteland we know today.