A strange discovery by NASA's Mars Curiosity rover suggests the Red Planet was home to an alien nuclear war 300 million years ago. Experts investigate if an extraterrestrial Armageddon transformed an earth-like world into the wasteland we know today.

Experts investigate if a nearby exoplanet could be the home to a alien civilization of strange, metallic monsters, after a new discovery confirms that life can thrive on such a strange world.

When NASA begins a strange experiment to communicate with dolphins, experts investigate if it's a prelude to making alien contact. But some fear that such a discovery could have apocalyptic consequences.

After Neil Armstrong's moonwalk, he led an expedition to the Amazon to find a legendary library that holds all knowledge of an advanced alien civilization. Experts ask if a close encounter on the moon's surface inspired Armstrong's mysterious quest.

After NASA's New Horizons spacecraft flies by Pluto, it encounters a strange alien world that shuts down the probe's computers, and experts investigate if this mysterious object is an alien spacecraft hiding at the edge of our solar system.

When astronomers discover a rogue black hole speeding through the Milky Way, they investigate how much danger this cosmic monster poses to Earth, and what would happen if it ever entered our solar system.

When a former Area 51 insider alleges that the Roswell UFO incident was a nefarious Soviet conspiracy masterminded by Stalin, experts investigate if it was indeed an enemy plot against America -- or if the confession is just another cover-up.

When NASA discovers something strange on Saturn's biggest moon, experts investigate if aliens feeding on the electric atmosphere could be the culprit. The disturbing evidence points to a grisly apocalypse if these monsters ever make it to Earth.